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createplan.c
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1 /*-------------------------------------------------------------------------
2  *
3  * createplan.c
4  * Routines to create the desired plan for processing a query.
5  * Planning is complete, we just need to convert the selected
6  * Path into a Plan.
7  *
8  * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
9  * Portions Copyright (c) 1994, Regents of the University of California
10  *
11  *
12  * IDENTIFICATION
13  * src/backend/optimizer/plan/createplan.c
14  *
15  *-------------------------------------------------------------------------
16  */
17 #include "postgres.h"
18 
19 #include <math.h>
20 
21 #include "access/sysattr.h"
22 #include "catalog/pg_class.h"
23 #include "foreign/fdwapi.h"
24 #include "miscadmin.h"
25 #include "nodes/extensible.h"
26 #include "nodes/makefuncs.h"
27 #include "nodes/nodeFuncs.h"
28 #include "optimizer/clauses.h"
29 #include "optimizer/cost.h"
30 #include "optimizer/optimizer.h"
31 #include "optimizer/paramassign.h"
32 #include "optimizer/paths.h"
33 #include "optimizer/placeholder.h"
34 #include "optimizer/plancat.h"
35 #include "optimizer/planmain.h"
36 #include "optimizer/prep.h"
37 #include "optimizer/restrictinfo.h"
38 #include "optimizer/subselect.h"
39 #include "optimizer/tlist.h"
40 #include "parser/parse_clause.h"
41 #include "parser/parsetree.h"
42 #include "partitioning/partprune.h"
43 #include "utils/lsyscache.h"
44 
45 
46 /*
47  * Flag bits that can appear in the flags argument of create_plan_recurse().
48  * These can be OR-ed together.
49  *
50  * CP_EXACT_TLIST specifies that the generated plan node must return exactly
51  * the tlist specified by the path's pathtarget (this overrides both
52  * CP_SMALL_TLIST and CP_LABEL_TLIST, if those are set). Otherwise, the
53  * plan node is allowed to return just the Vars and PlaceHolderVars needed
54  * to evaluate the pathtarget.
55  *
56  * CP_SMALL_TLIST specifies that a narrower tlist is preferred. This is
57  * passed down by parent nodes such as Sort and Hash, which will have to
58  * store the returned tuples.
59  *
60  * CP_LABEL_TLIST specifies that the plan node must return columns matching
61  * any sortgrouprefs specified in its pathtarget, with appropriate
62  * ressortgroupref labels. This is passed down by parent nodes such as Sort
63  * and Group, which need these values to be available in their inputs.
64  *
65  * CP_IGNORE_TLIST specifies that the caller plans to replace the targetlist,
66  * and therefore it doesn't matter a bit what target list gets generated.
67  */
68 #define CP_EXACT_TLIST 0x0001 /* Plan must return specified tlist */
69 #define CP_SMALL_TLIST 0x0002 /* Prefer narrower tlists */
70 #define CP_LABEL_TLIST 0x0004 /* tlist must contain sortgrouprefs */
71 #define CP_IGNORE_TLIST 0x0008 /* caller will replace tlist */
72 
73 
74 static Plan *create_plan_recurse(PlannerInfo *root, Path *best_path,
75  int flags);
76 static Plan *create_scan_plan(PlannerInfo *root, Path *best_path,
77  int flags);
78 static List *build_path_tlist(PlannerInfo *root, Path *path);
79 static bool use_physical_tlist(PlannerInfo *root, Path *path, int flags);
80 static List *get_gating_quals(PlannerInfo *root, List *quals);
81 static Plan *create_gating_plan(PlannerInfo *root, Path *path, Plan *plan,
82  List *gating_quals);
83 static Plan *create_join_plan(PlannerInfo *root, JoinPath *best_path);
84 static bool mark_async_capable_plan(Plan *plan, Path *path);
85 static Plan *create_append_plan(PlannerInfo *root, AppendPath *best_path,
86  int flags);
87 static Plan *create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path,
88  int flags);
89 static Result *create_group_result_plan(PlannerInfo *root,
90  GroupResultPath *best_path);
91 static ProjectSet *create_project_set_plan(PlannerInfo *root, ProjectSetPath *best_path);
92 static Material *create_material_plan(PlannerInfo *root, MaterialPath *best_path,
93  int flags);
94 static Memoize *create_memoize_plan(PlannerInfo *root, MemoizePath *best_path,
95  int flags);
96 static Plan *create_unique_plan(PlannerInfo *root, UniquePath *best_path,
97  int flags);
98 static Gather *create_gather_plan(PlannerInfo *root, GatherPath *best_path);
99 static Plan *create_projection_plan(PlannerInfo *root,
100  ProjectionPath *best_path,
101  int flags);
102 static Plan *inject_projection_plan(Plan *subplan, List *tlist, bool parallel_safe);
103 static Sort *create_sort_plan(PlannerInfo *root, SortPath *best_path, int flags);
104 static IncrementalSort *create_incrementalsort_plan(PlannerInfo *root,
105  IncrementalSortPath *best_path, int flags);
106 static Group *create_group_plan(PlannerInfo *root, GroupPath *best_path);
107 static Unique *create_upper_unique_plan(PlannerInfo *root, UpperUniquePath *best_path,
108  int flags);
109 static Agg *create_agg_plan(PlannerInfo *root, AggPath *best_path);
110 static Plan *create_groupingsets_plan(PlannerInfo *root, GroupingSetsPath *best_path);
111 static Result *create_minmaxagg_plan(PlannerInfo *root, MinMaxAggPath *best_path);
112 static WindowAgg *create_windowagg_plan(PlannerInfo *root, WindowAggPath *best_path);
113 static SetOp *create_setop_plan(PlannerInfo *root, SetOpPath *best_path,
114  int flags);
115 static RecursiveUnion *create_recursiveunion_plan(PlannerInfo *root, RecursiveUnionPath *best_path);
116 static LockRows *create_lockrows_plan(PlannerInfo *root, LockRowsPath *best_path,
117  int flags);
118 static ModifyTable *create_modifytable_plan(PlannerInfo *root, ModifyTablePath *best_path);
119 static Limit *create_limit_plan(PlannerInfo *root, LimitPath *best_path,
120  int flags);
121 static SeqScan *create_seqscan_plan(PlannerInfo *root, Path *best_path,
122  List *tlist, List *scan_clauses);
123 static SampleScan *create_samplescan_plan(PlannerInfo *root, Path *best_path,
124  List *tlist, List *scan_clauses);
125 static Scan *create_indexscan_plan(PlannerInfo *root, IndexPath *best_path,
126  List *tlist, List *scan_clauses, bool indexonly);
127 static BitmapHeapScan *create_bitmap_scan_plan(PlannerInfo *root,
128  BitmapHeapPath *best_path,
129  List *tlist, List *scan_clauses);
130 static Plan *create_bitmap_subplan(PlannerInfo *root, Path *bitmapqual,
131  List **qual, List **indexqual, List **indexECs);
132 static void bitmap_subplan_mark_shared(Plan *plan);
133 static TidScan *create_tidscan_plan(PlannerInfo *root, TidPath *best_path,
134  List *tlist, List *scan_clauses);
135 static TidRangeScan *create_tidrangescan_plan(PlannerInfo *root,
136  TidRangePath *best_path,
137  List *tlist,
138  List *scan_clauses);
139 static SubqueryScan *create_subqueryscan_plan(PlannerInfo *root,
140  SubqueryScanPath *best_path,
141  List *tlist, List *scan_clauses);
142 static FunctionScan *create_functionscan_plan(PlannerInfo *root, Path *best_path,
143  List *tlist, List *scan_clauses);
144 static ValuesScan *create_valuesscan_plan(PlannerInfo *root, Path *best_path,
145  List *tlist, List *scan_clauses);
146 static TableFuncScan *create_tablefuncscan_plan(PlannerInfo *root, Path *best_path,
147  List *tlist, List *scan_clauses);
148 static CteScan *create_ctescan_plan(PlannerInfo *root, Path *best_path,
149  List *tlist, List *scan_clauses);
150 static NamedTuplestoreScan *create_namedtuplestorescan_plan(PlannerInfo *root,
151  Path *best_path, List *tlist, List *scan_clauses);
152 static Result *create_resultscan_plan(PlannerInfo *root, Path *best_path,
153  List *tlist, List *scan_clauses);
154 static WorkTableScan *create_worktablescan_plan(PlannerInfo *root, Path *best_path,
155  List *tlist, List *scan_clauses);
156 static ForeignScan *create_foreignscan_plan(PlannerInfo *root, ForeignPath *best_path,
157  List *tlist, List *scan_clauses);
158 static CustomScan *create_customscan_plan(PlannerInfo *root,
159  CustomPath *best_path,
160  List *tlist, List *scan_clauses);
161 static NestLoop *create_nestloop_plan(PlannerInfo *root, NestPath *best_path);
162 static MergeJoin *create_mergejoin_plan(PlannerInfo *root, MergePath *best_path);
163 static HashJoin *create_hashjoin_plan(PlannerInfo *root, HashPath *best_path);
164 static Node *replace_nestloop_params(PlannerInfo *root, Node *expr);
165 static Node *replace_nestloop_params_mutator(Node *node, PlannerInfo *root);
166 static void fix_indexqual_references(PlannerInfo *root, IndexPath *index_path,
167  List **stripped_indexquals_p,
168  List **fixed_indexquals_p);
169 static List *fix_indexorderby_references(PlannerInfo *root, IndexPath *index_path);
170 static Node *fix_indexqual_clause(PlannerInfo *root,
171  IndexOptInfo *index, int indexcol,
172  Node *clause, List *indexcolnos);
173 static Node *fix_indexqual_operand(Node *node, IndexOptInfo *index, int indexcol);
174 static List *get_switched_clauses(List *clauses, Relids outerrelids);
175 static List *order_qual_clauses(PlannerInfo *root, List *clauses);
176 static void copy_generic_path_info(Plan *dest, Path *src);
177 static void copy_plan_costsize(Plan *dest, Plan *src);
178 static void label_sort_with_costsize(PlannerInfo *root, Sort *plan,
179  double limit_tuples);
180 static SeqScan *make_seqscan(List *qptlist, List *qpqual, Index scanrelid);
181 static SampleScan *make_samplescan(List *qptlist, List *qpqual, Index scanrelid,
182  TableSampleClause *tsc);
183 static IndexScan *make_indexscan(List *qptlist, List *qpqual, Index scanrelid,
184  Oid indexid, List *indexqual, List *indexqualorig,
185  List *indexorderby, List *indexorderbyorig,
186  List *indexorderbyops,
187  ScanDirection indexscandir);
188 static IndexOnlyScan *make_indexonlyscan(List *qptlist, List *qpqual,
189  Index scanrelid, Oid indexid,
190  List *indexqual, List *recheckqual,
191  List *indexorderby,
192  List *indextlist,
193  ScanDirection indexscandir);
194 static BitmapIndexScan *make_bitmap_indexscan(Index scanrelid, Oid indexid,
195  List *indexqual,
196  List *indexqualorig);
197 static BitmapHeapScan *make_bitmap_heapscan(List *qptlist,
198  List *qpqual,
199  Plan *lefttree,
200  List *bitmapqualorig,
201  Index scanrelid);
202 static TidScan *make_tidscan(List *qptlist, List *qpqual, Index scanrelid,
203  List *tidquals);
204 static TidRangeScan *make_tidrangescan(List *qptlist, List *qpqual,
205  Index scanrelid, List *tidrangequals);
206 static SubqueryScan *make_subqueryscan(List *qptlist,
207  List *qpqual,
208  Index scanrelid,
209  Plan *subplan);
210 static FunctionScan *make_functionscan(List *qptlist, List *qpqual,
211  Index scanrelid, List *functions, bool funcordinality);
212 static ValuesScan *make_valuesscan(List *qptlist, List *qpqual,
213  Index scanrelid, List *values_lists);
214 static TableFuncScan *make_tablefuncscan(List *qptlist, List *qpqual,
215  Index scanrelid, TableFunc *tablefunc);
216 static CteScan *make_ctescan(List *qptlist, List *qpqual,
217  Index scanrelid, int ctePlanId, int cteParam);
218 static NamedTuplestoreScan *make_namedtuplestorescan(List *qptlist, List *qpqual,
219  Index scanrelid, char *enrname);
220 static WorkTableScan *make_worktablescan(List *qptlist, List *qpqual,
221  Index scanrelid, int wtParam);
222 static RecursiveUnion *make_recursive_union(List *tlist,
223  Plan *lefttree,
224  Plan *righttree,
225  int wtParam,
226  List *distinctList,
227  long numGroups);
228 static BitmapAnd *make_bitmap_and(List *bitmapplans);
229 static BitmapOr *make_bitmap_or(List *bitmapplans);
230 static NestLoop *make_nestloop(List *tlist,
231  List *joinclauses, List *otherclauses, List *nestParams,
232  Plan *lefttree, Plan *righttree,
233  JoinType jointype, bool inner_unique);
234 static HashJoin *make_hashjoin(List *tlist,
235  List *joinclauses, List *otherclauses,
236  List *hashclauses,
237  List *hashoperators, List *hashcollations,
238  List *hashkeys,
239  Plan *lefttree, Plan *righttree,
240  JoinType jointype, bool inner_unique);
241 static Hash *make_hash(Plan *lefttree,
242  List *hashkeys,
243  Oid skewTable,
244  AttrNumber skewColumn,
245  bool skewInherit);
246 static MergeJoin *make_mergejoin(List *tlist,
247  List *joinclauses, List *otherclauses,
248  List *mergeclauses,
249  Oid *mergefamilies,
250  Oid *mergecollations,
251  int *mergestrategies,
252  bool *mergenullsfirst,
253  Plan *lefttree, Plan *righttree,
254  JoinType jointype, bool inner_unique,
255  bool skip_mark_restore);
256 static Sort *make_sort(Plan *lefttree, int numCols,
257  AttrNumber *sortColIdx, Oid *sortOperators,
258  Oid *collations, bool *nullsFirst);
259 static IncrementalSort *make_incrementalsort(Plan *lefttree,
260  int numCols, int nPresortedCols,
261  AttrNumber *sortColIdx, Oid *sortOperators,
262  Oid *collations, bool *nullsFirst);
263 static Plan *prepare_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
264  Relids relids,
265  const AttrNumber *reqColIdx,
266  bool adjust_tlist_in_place,
267  int *p_numsortkeys,
268  AttrNumber **p_sortColIdx,
269  Oid **p_sortOperators,
270  Oid **p_collations,
271  bool **p_nullsFirst);
272 static Sort *make_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
273  Relids relids);
274 static IncrementalSort *make_incrementalsort_from_pathkeys(Plan *lefttree,
275  List *pathkeys, Relids relids, int nPresortedCols);
276 static Sort *make_sort_from_groupcols(List *groupcls,
277  AttrNumber *grpColIdx,
278  Plan *lefttree);
279 static Material *make_material(Plan *lefttree);
280 static Memoize *make_memoize(Plan *lefttree, Oid *hashoperators,
281  Oid *collations, List *param_exprs,
282  bool singlerow, bool binary_mode,
283  uint32 est_entries, Bitmapset *keyparamids);
284 static WindowAgg *make_windowagg(List *tlist, Index winref,
285  int partNumCols, AttrNumber *partColIdx, Oid *partOperators, Oid *partCollations,
286  int ordNumCols, AttrNumber *ordColIdx, Oid *ordOperators, Oid *ordCollations,
287  int frameOptions, Node *startOffset, Node *endOffset,
288  Oid startInRangeFunc, Oid endInRangeFunc,
289  Oid inRangeColl, bool inRangeAsc, bool inRangeNullsFirst,
290  List *runCondition, List *qual, bool topWindow,
291  Plan *lefttree);
292 static Group *make_group(List *tlist, List *qual, int numGroupCols,
293  AttrNumber *grpColIdx, Oid *grpOperators, Oid *grpCollations,
294  Plan *lefttree);
295 static Unique *make_unique_from_sortclauses(Plan *lefttree, List *distinctList);
296 static Unique *make_unique_from_pathkeys(Plan *lefttree,
297  List *pathkeys, int numCols);
298 static Gather *make_gather(List *qptlist, List *qpqual,
299  int nworkers, int rescan_param, bool single_copy, Plan *subplan);
300 static SetOp *make_setop(SetOpCmd cmd, SetOpStrategy strategy, Plan *lefttree,
301  List *distinctList, AttrNumber flagColIdx, int firstFlag,
302  long numGroups);
303 static LockRows *make_lockrows(Plan *lefttree, List *rowMarks, int epqParam);
304 static Result *make_result(List *tlist, Node *resconstantqual, Plan *subplan);
305 static ProjectSet *make_project_set(List *tlist, Plan *subplan);
306 static ModifyTable *make_modifytable(PlannerInfo *root, Plan *subplan,
307  CmdType operation, bool canSetTag,
308  Index nominalRelation, Index rootRelation,
309  bool partColsUpdated,
310  List *resultRelations,
311  List *updateColnosLists,
312  List *withCheckOptionLists, List *returningLists,
313  List *rowMarks, OnConflictExpr *onconflict,
314  List *mergeActionList, int epqParam);
315 static GatherMerge *create_gather_merge_plan(PlannerInfo *root,
316  GatherMergePath *best_path);
317 
318 
319 /*
320  * create_plan
321  * Creates the access plan for a query by recursively processing the
322  * desired tree of pathnodes, starting at the node 'best_path'. For
323  * every pathnode found, we create a corresponding plan node containing
324  * appropriate id, target list, and qualification information.
325  *
326  * The tlists and quals in the plan tree are still in planner format,
327  * ie, Vars still correspond to the parser's numbering. This will be
328  * fixed later by setrefs.c.
329  *
330  * best_path is the best access path
331  *
332  * Returns a Plan tree.
333  */
334 Plan *
335 create_plan(PlannerInfo *root, Path *best_path)
336 {
337  Plan *plan;
338 
339  /* plan_params should not be in use in current query level */
340  Assert(root->plan_params == NIL);
341 
342  /* Initialize this module's workspace in PlannerInfo */
343  root->curOuterRels = NULL;
344  root->curOuterParams = NIL;
345 
346  /* Recursively process the path tree, demanding the correct tlist result */
347  plan = create_plan_recurse(root, best_path, CP_EXACT_TLIST);
348 
349  /*
350  * Make sure the topmost plan node's targetlist exposes the original
351  * column names and other decorative info. Targetlists generated within
352  * the planner don't bother with that stuff, but we must have it on the
353  * top-level tlist seen at execution time. However, ModifyTable plan
354  * nodes don't have a tlist matching the querytree targetlist.
355  */
356  if (!IsA(plan, ModifyTable))
357  apply_tlist_labeling(plan->targetlist, root->processed_tlist);
358 
359  /*
360  * Attach any initPlans created in this query level to the topmost plan
361  * node. (In principle the initplans could go in any plan node at or
362  * above where they're referenced, but there seems no reason to put them
363  * any lower than the topmost node for the query level. Also, see
364  * comments for SS_finalize_plan before you try to change this.)
365  */
366  SS_attach_initplans(root, plan);
367 
368  /* Check we successfully assigned all NestLoopParams to plan nodes */
369  if (root->curOuterParams != NIL)
370  elog(ERROR, "failed to assign all NestLoopParams to plan nodes");
371 
372  /*
373  * Reset plan_params to ensure param IDs used for nestloop params are not
374  * re-used later
375  */
376  root->plan_params = NIL;
377 
378  return plan;
379 }
380 
381 /*
382  * create_plan_recurse
383  * Recursive guts of create_plan().
384  */
385 static Plan *
386 create_plan_recurse(PlannerInfo *root, Path *best_path, int flags)
387 {
388  Plan *plan;
389 
390  /* Guard against stack overflow due to overly complex plans */
391  check_stack_depth();
392 
393  switch (best_path->pathtype)
394  {
395  case T_SeqScan:
396  case T_SampleScan:
397  case T_IndexScan:
398  case T_IndexOnlyScan:
399  case T_BitmapHeapScan:
400  case T_TidScan:
401  case T_TidRangeScan:
402  case T_SubqueryScan:
403  case T_FunctionScan:
404  case T_TableFuncScan:
405  case T_ValuesScan:
406  case T_CteScan:
407  case T_WorkTableScan:
408  case T_NamedTuplestoreScan:
409  case T_ForeignScan:
410  case T_CustomScan:
411  plan = create_scan_plan(root, best_path, flags);
412  break;
413  case T_HashJoin:
414  case T_MergeJoin:
415  case T_NestLoop:
416  plan = create_join_plan(root,
417  (JoinPath *) best_path);
418  break;
419  case T_Append:
420  plan = create_append_plan(root,
421  (AppendPath *) best_path,
422  flags);
423  break;
424  case T_MergeAppend:
425  plan = create_merge_append_plan(root,
426  (MergeAppendPath *) best_path,
427  flags);
428  break;
429  case T_Result:
430  if (IsA(best_path, ProjectionPath))
431  {
432  plan = create_projection_plan(root,
433  (ProjectionPath *) best_path,
434  flags);
435  }
436  else if (IsA(best_path, MinMaxAggPath))
437  {
438  plan = (Plan *) create_minmaxagg_plan(root,
439  (MinMaxAggPath *) best_path);
440  }
441  else if (IsA(best_path, GroupResultPath))
442  {
443  plan = (Plan *) create_group_result_plan(root,
444  (GroupResultPath *) best_path);
445  }
446  else
447  {
448  /* Simple RTE_RESULT base relation */
449  Assert(IsA(best_path, Path));
450  plan = create_scan_plan(root, best_path, flags);
451  }
452  break;
453  case T_ProjectSet:
454  plan = (Plan *) create_project_set_plan(root,
455  (ProjectSetPath *) best_path);
456  break;
457  case T_Material:
458  plan = (Plan *) create_material_plan(root,
459  (MaterialPath *) best_path,
460  flags);
461  break;
462  case T_Memoize:
463  plan = (Plan *) create_memoize_plan(root,
464  (MemoizePath *) best_path,
465  flags);
466  break;
467  case T_Unique:
468  if (IsA(best_path, UpperUniquePath))
469  {
470  plan = (Plan *) create_upper_unique_plan(root,
471  (UpperUniquePath *) best_path,
472  flags);
473  }
474  else
475  {
476  Assert(IsA(best_path, UniquePath));
477  plan = create_unique_plan(root,
478  (UniquePath *) best_path,
479  flags);
480  }
481  break;
482  case T_Gather:
483  plan = (Plan *) create_gather_plan(root,
484  (GatherPath *) best_path);
485  break;
486  case T_Sort:
487  plan = (Plan *) create_sort_plan(root,
488  (SortPath *) best_path,
489  flags);
490  break;
491  case T_IncrementalSort:
492  plan = (Plan *) create_incrementalsort_plan(root,
493  (IncrementalSortPath *) best_path,
494  flags);
495  break;
496  case T_Group:
497  plan = (Plan *) create_group_plan(root,
498  (GroupPath *) best_path);
499  break;
500  case T_Agg:
501  if (IsA(best_path, GroupingSetsPath))
502  plan = create_groupingsets_plan(root,
503  (GroupingSetsPath *) best_path);
504  else
505  {
506  Assert(IsA(best_path, AggPath));
507  plan = (Plan *) create_agg_plan(root,
508  (AggPath *) best_path);
509  }
510  break;
511  case T_WindowAgg:
512  plan = (Plan *) create_windowagg_plan(root,
513  (WindowAggPath *) best_path);
514  break;
515  case T_SetOp:
516  plan = (Plan *) create_setop_plan(root,
517  (SetOpPath *) best_path,
518  flags);
519  break;
520  case T_RecursiveUnion:
521  plan = (Plan *) create_recursiveunion_plan(root,
522  (RecursiveUnionPath *) best_path);
523  break;
524  case T_LockRows:
525  plan = (Plan *) create_lockrows_plan(root,
526  (LockRowsPath *) best_path,
527  flags);
528  break;
529  case T_ModifyTable:
530  plan = (Plan *) create_modifytable_plan(root,
531  (ModifyTablePath *) best_path);
532  break;
533  case T_Limit:
534  plan = (Plan *) create_limit_plan(root,
535  (LimitPath *) best_path,
536  flags);
537  break;
538  case T_GatherMerge:
539  plan = (Plan *) create_gather_merge_plan(root,
540  (GatherMergePath *) best_path);
541  break;
542  default:
543  elog(ERROR, "unrecognized node type: %d",
544  (int) best_path->pathtype);
545  plan = NULL; /* keep compiler quiet */
546  break;
547  }
548 
549  return plan;
550 }
551 
552 /*
553  * create_scan_plan
554  * Create a scan plan for the parent relation of 'best_path'.
555  */
556 static Plan *
557 create_scan_plan(PlannerInfo *root, Path *best_path, int flags)
558 {
559  RelOptInfo *rel = best_path->parent;
560  List *scan_clauses;
561  List *gating_clauses;
562  List *tlist;
563  Plan *plan;
564 
565  /*
566  * Extract the relevant restriction clauses from the parent relation. The
567  * executor must apply all these restrictions during the scan, except for
568  * pseudoconstants which we'll take care of below.
569  *
570  * If this is a plain indexscan or index-only scan, we need not consider
571  * restriction clauses that are implied by the index's predicate, so use
572  * indrestrictinfo not baserestrictinfo. Note that we can't do that for
573  * bitmap indexscans, since there's not necessarily a single index
574  * involved; but it doesn't matter since create_bitmap_scan_plan() will be
575  * able to get rid of such clauses anyway via predicate proof.
576  */
577  switch (best_path->pathtype)
578  {
579  case T_IndexScan:
580  case T_IndexOnlyScan:
581  scan_clauses = castNode(IndexPath, best_path)->indexinfo->indrestrictinfo;
582  break;
583  default:
584  scan_clauses = rel->baserestrictinfo;
585  break;
586  }
587 
588  /*
589  * If this is a parameterized scan, we also need to enforce all the join
590  * clauses available from the outer relation(s).
591  *
592  * For paranoia's sake, don't modify the stored baserestrictinfo list.
593  */
594  if (best_path->param_info)
595  scan_clauses = list_concat_copy(scan_clauses,
596  best_path->param_info->ppi_clauses);
597 
598  /*
599  * Detect whether we have any pseudoconstant quals to deal with. Then, if
600  * we'll need a gating Result node, it will be able to project, so there
601  * are no requirements on the child's tlist.
602  */
603  gating_clauses = get_gating_quals(root, scan_clauses);
604  if (gating_clauses)
605  flags = 0;
606 
607  /*
608  * For table scans, rather than using the relation targetlist (which is
609  * only those Vars actually needed by the query), we prefer to generate a
610  * tlist containing all Vars in order. This will allow the executor to
611  * optimize away projection of the table tuples, if possible.
612  *
613  * But if the caller is going to ignore our tlist anyway, then don't
614  * bother generating one at all. We use an exact equality test here, so
615  * that this only applies when CP_IGNORE_TLIST is the only flag set.
616  */
617  if (flags == CP_IGNORE_TLIST)
618  {
619  tlist = NULL;
620  }
621  else if (use_physical_tlist(root, best_path, flags))
622  {
623  if (best_path->pathtype == T_IndexOnlyScan)
624  {
625  /* For index-only scan, the preferred tlist is the index's */
626  tlist = copyObject(((IndexPath *) best_path)->indexinfo->indextlist);
627 
628  /*
629  * Transfer sortgroupref data to the replacement tlist, if
630  * requested (use_physical_tlist checked that this will work).
631  */
632  if (flags & CP_LABEL_TLIST)
633  apply_pathtarget_labeling_to_tlist(tlist, best_path->pathtarget);
634  }
635  else
636  {
637  tlist = build_physical_tlist(root, rel);
638  if (tlist == NIL)
639  {
640  /* Failed because of dropped cols, so use regular method */
641  tlist = build_path_tlist(root, best_path);
642  }
643  else
644  {
645  /* As above, transfer sortgroupref data to replacement tlist */
646  if (flags & CP_LABEL_TLIST)
647  apply_pathtarget_labeling_to_tlist(tlist, best_path->pathtarget);
648  }
649  }
650  }
651  else
652  {
653  tlist = build_path_tlist(root, best_path);
654  }
655 
656  switch (best_path->pathtype)
657  {
658  case T_SeqScan:
659  plan = (Plan *) create_seqscan_plan(root,
660  best_path,
661  tlist,
662  scan_clauses);
663  break;
664 
665  case T_SampleScan:
666  plan = (Plan *) create_samplescan_plan(root,
667  best_path,
668  tlist,
669  scan_clauses);
670  break;
671 
672  case T_IndexScan:
673  plan = (Plan *) create_indexscan_plan(root,
674  (IndexPath *) best_path,
675  tlist,
676  scan_clauses,
677  false);
678  break;
679 
680  case T_IndexOnlyScan:
681  plan = (Plan *) create_indexscan_plan(root,
682  (IndexPath *) best_path,
683  tlist,
684  scan_clauses,
685  true);
686  break;
687 
688  case T_BitmapHeapScan:
689  plan = (Plan *) create_bitmap_scan_plan(root,
690  (BitmapHeapPath *) best_path,
691  tlist,
692  scan_clauses);
693  break;
694 
695  case T_TidScan:
696  plan = (Plan *) create_tidscan_plan(root,
697  (TidPath *) best_path,
698  tlist,
699  scan_clauses);
700  break;
701 
702  case T_TidRangeScan:
703  plan = (Plan *) create_tidrangescan_plan(root,
704  (TidRangePath *) best_path,
705  tlist,
706  scan_clauses);
707  break;
708 
709  case T_SubqueryScan:
710  plan = (Plan *) create_subqueryscan_plan(root,
711  (SubqueryScanPath *) best_path,
712  tlist,
713  scan_clauses);
714  break;
715 
716  case T_FunctionScan:
717  plan = (Plan *) create_functionscan_plan(root,
718  best_path,
719  tlist,
720  scan_clauses);
721  break;
722 
723  case T_TableFuncScan:
724  plan = (Plan *) create_tablefuncscan_plan(root,
725  best_path,
726  tlist,
727  scan_clauses);
728  break;
729 
730  case T_ValuesScan:
731  plan = (Plan *) create_valuesscan_plan(root,
732  best_path,
733  tlist,
734  scan_clauses);
735  break;
736 
737  case T_CteScan:
738  plan = (Plan *) create_ctescan_plan(root,
739  best_path,
740  tlist,
741  scan_clauses);
742  break;
743 
744  case T_NamedTuplestoreScan:
745  plan = (Plan *) create_namedtuplestorescan_plan(root,
746  best_path,
747  tlist,
748  scan_clauses);
749  break;
750 
751  case T_Result:
752  plan = (Plan *) create_resultscan_plan(root,
753  best_path,
754  tlist,
755  scan_clauses);
756  break;
757 
758  case T_WorkTableScan:
759  plan = (Plan *) create_worktablescan_plan(root,
760  best_path,
761  tlist,
762  scan_clauses);
763  break;
764 
765  case T_ForeignScan:
766  plan = (Plan *) create_foreignscan_plan(root,
767  (ForeignPath *) best_path,
768  tlist,
769  scan_clauses);
770  break;
771 
772  case T_CustomScan:
773  plan = (Plan *) create_customscan_plan(root,
774  (CustomPath *) best_path,
775  tlist,
776  scan_clauses);
777  break;
778 
779  default:
780  elog(ERROR, "unrecognized node type: %d",
781  (int) best_path->pathtype);
782  plan = NULL; /* keep compiler quiet */
783  break;
784  }
785 
786  /*
787  * If there are any pseudoconstant clauses attached to this node, insert a
788  * gating Result node that evaluates the pseudoconstants as one-time
789  * quals.
790  */
791  if (gating_clauses)
792  plan = create_gating_plan(root, best_path, plan, gating_clauses);
793 
794  return plan;
795 }
796 
797 /*
798  * Build a target list (ie, a list of TargetEntry) for the Path's output.
799  *
800  * This is almost just make_tlist_from_pathtarget(), but we also have to
801  * deal with replacing nestloop params.
802  */
803 static List *
804 build_path_tlist(PlannerInfo *root, Path *path)
805 {
806  List *tlist = NIL;
807  Index *sortgrouprefs = path->pathtarget->sortgrouprefs;
808  int resno = 1;
809  ListCell *v;
810 
811  foreach(v, path->pathtarget->exprs)
812  {
813  Node *node = (Node *) lfirst(v);
814  TargetEntry *tle;
815 
816  /*
817  * If it's a parameterized path, there might be lateral references in
818  * the tlist, which need to be replaced with Params. There's no need
819  * to remake the TargetEntry nodes, so apply this to each list item
820  * separately.
821  */
822  if (path->param_info)
823  node = replace_nestloop_params(root, node);
824 
825  tle = makeTargetEntry((Expr *) node,
826  resno,
827  NULL,
828  false);
829  if (sortgrouprefs)
830  tle->ressortgroupref = sortgrouprefs[resno - 1];
831 
832  tlist = lappend(tlist, tle);
833  resno++;
834  }
835  return tlist;
836 }
837 
838 /*
839  * use_physical_tlist
840  * Decide whether to use a tlist matching relation structure,
841  * rather than only those Vars actually referenced.
842  */
843 static bool
844 use_physical_tlist(PlannerInfo *root, Path *path, int flags)
845 {
846  RelOptInfo *rel = path->parent;
847  int i;
848  ListCell *lc;
849 
850  /*
851  * Forget it if either exact tlist or small tlist is demanded.
852  */
853  if (flags & (CP_EXACT_TLIST | CP_SMALL_TLIST))
854  return false;
855 
856  /*
857  * We can do this for real relation scans, subquery scans, function scans,
858  * tablefunc scans, values scans, and CTE scans (but not for, eg, joins).
859  */
860  if (rel->rtekind != RTE_RELATION &&
861  rel->rtekind != RTE_SUBQUERY &&
862  rel->rtekind != RTE_FUNCTION &&
863  rel->rtekind != RTE_TABLEFUNC &&
864  rel->rtekind != RTE_VALUES &&
865  rel->rtekind != RTE_CTE)
866  return false;
867 
868  /*
869  * Can't do it with inheritance cases either (mainly because Append
870  * doesn't project; this test may be unnecessary now that
871  * create_append_plan instructs its children to return an exact tlist).
872  */
873  if (rel->reloptkind != RELOPT_BASEREL)
874  return false;
875 
876  /*
877  * Also, don't do it to a CustomPath; the premise that we're extracting
878  * columns from a simple physical tuple is unlikely to hold for those.
879  * (When it does make sense, the custom path creator can set up the path's
880  * pathtarget that way.)
881  */
882  if (IsA(path, CustomPath))
883  return false;
884 
885  /*
886  * If a bitmap scan's tlist is empty, keep it as-is. This may allow the
887  * executor to skip heap page fetches, and in any case, the benefit of
888  * using a physical tlist instead would be minimal.
889  */
890  if (IsA(path, BitmapHeapPath) &&
891  path->pathtarget->exprs == NIL)
892  return false;
893 
894  /*
895  * Can't do it if any system columns or whole-row Vars are requested.
896  * (This could possibly be fixed but would take some fragile assumptions
897  * in setrefs.c, I think.)
898  */
899  for (i = rel->min_attr; i <= 0; i++)
900  {
901  if (!bms_is_empty(rel->attr_needed[i - rel->min_attr]))
902  return false;
903  }
904 
905  /*
906  * Can't do it if the rel is required to emit any placeholder expressions,
907  * either.
908  */
909  foreach(lc, root->placeholder_list)
910  {
911  PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(lc);
912 
913  if (bms_nonempty_difference(phinfo->ph_needed, rel->relids) &&
914  bms_is_subset(phinfo->ph_eval_at, rel->relids))
915  return false;
916  }
917 
918  /*
919  * For an index-only scan, the "physical tlist" is the index's indextlist.
920  * We can only return that without a projection if all the index's columns
921  * are returnable.
922  */
923  if (path->pathtype == T_IndexOnlyScan)
924  {
925  IndexOptInfo *indexinfo = ((IndexPath *) path)->indexinfo;
926 
927  for (i = 0; i < indexinfo->ncolumns; i++)
928  {
929  if (!indexinfo->canreturn[i])
930  return false;
931  }
932  }
933 
934  /*
935  * Also, can't do it if CP_LABEL_TLIST is specified and path is requested
936  * to emit any sort/group columns that are not simple Vars. (If they are
937  * simple Vars, they should appear in the physical tlist, and
938  * apply_pathtarget_labeling_to_tlist will take care of getting them
939  * labeled again.) We also have to check that no two sort/group columns
940  * are the same Var, else that element of the physical tlist would need
941  * conflicting ressortgroupref labels.
942  */
943  if ((flags & CP_LABEL_TLIST) && path->pathtarget->sortgrouprefs)
944  {
945  Bitmapset *sortgroupatts = NULL;
946 
947  i = 0;
948  foreach(lc, path->pathtarget->exprs)
949  {
950  Expr *expr = (Expr *) lfirst(lc);
951 
952  if (path->pathtarget->sortgrouprefs[i])
953  {
954  if (expr && IsA(expr, Var))
955  {
956  int attno = ((Var *) expr)->varattno;
957 
958  attno -= FirstLowInvalidHeapAttributeNumber;
959  if (bms_is_member(attno, sortgroupatts))
960  return false;
961  sortgroupatts = bms_add_member(sortgroupatts, attno);
962  }
963  else
964  return false;
965  }
966  i++;
967  }
968  }
969 
970  return true;
971 }
972 
973 /*
974  * get_gating_quals
975  * See if there are pseudoconstant quals in a node's quals list
976  *
977  * If the node's quals list includes any pseudoconstant quals,
978  * return just those quals.
979  */
980 static List *
981 get_gating_quals(PlannerInfo *root, List *quals)
982 {
983  /* No need to look if we know there are no pseudoconstants */
984  if (!root->hasPseudoConstantQuals)
985  return NIL;
986 
987  /* Sort into desirable execution order while still in RestrictInfo form */
988  quals = order_qual_clauses(root, quals);
989 
990  /* Pull out any pseudoconstant quals from the RestrictInfo list */
991  return extract_actual_clauses(quals, true);
992 }
993 
994 /*
995  * create_gating_plan
996  * Deal with pseudoconstant qual clauses
997  *
998  * Add a gating Result node atop the already-built plan.
999  */
1000 static Plan *
1001 create_gating_plan(PlannerInfo *root, Path *path, Plan *plan,
1002  List *gating_quals)
1003 {
1004  Plan *gplan;
1005  Plan *splan;
1006 
1007  Assert(gating_quals);
1008 
1009  /*
1010  * We might have a trivial Result plan already. Stacking one Result atop
1011  * another is silly, so if that applies, just discard the input plan.
1012  * (We're assuming its targetlist is uninteresting; it should be either
1013  * the same as the result of build_path_tlist, or a simplified version.)
1014  */
1015  splan = plan;
1016  if (IsA(plan, Result))
1017  {
1018  Result *rplan = (Result *) plan;
1019 
1020  if (rplan->plan.lefttree == NULL &&
1021  rplan->resconstantqual == NULL)
1022  splan = NULL;
1023  }
1024 
1025  /*
1026  * Since we need a Result node anyway, always return the path's requested
1027  * tlist; that's never a wrong choice, even if the parent node didn't ask
1028  * for CP_EXACT_TLIST.
1029  */
1030  gplan = (Plan *) make_result(build_path_tlist(root, path),
1031  (Node *) gating_quals,
1032  splan);
1033 
1034  /*
1035  * Notice that we don't change cost or size estimates when doing gating.
1036  * The costs of qual eval were already included in the subplan's cost.
1037  * Leaving the size alone amounts to assuming that the gating qual will
1038  * succeed, which is the conservative estimate for planning upper queries.
1039  * We certainly don't want to assume the output size is zero (unless the
1040  * gating qual is actually constant FALSE, and that case is dealt with in
1041  * clausesel.c). Interpolating between the two cases is silly, because it
1042  * doesn't reflect what will really happen at runtime, and besides which
1043  * in most cases we have only a very bad idea of the probability of the
1044  * gating qual being true.
1045  */
1046  copy_plan_costsize(gplan, plan);
1047 
1048  /* Gating quals could be unsafe, so better use the Path's safety flag */
1049  gplan->parallel_safe = path->parallel_safe;
1050 
1051  return gplan;
1052 }
1053 
1054 /*
1055  * create_join_plan
1056  * Create a join plan for 'best_path' and (recursively) plans for its
1057  * inner and outer paths.
1058  */
1059 static Plan *
1060 create_join_plan(PlannerInfo *root, JoinPath *best_path)
1061 {
1062  Plan *plan;
1063  List *gating_clauses;
1064 
1065  switch (best_path->path.pathtype)
1066  {
1067  case T_MergeJoin:
1068  plan = (Plan *) create_mergejoin_plan(root,
1069  (MergePath *) best_path);
1070  break;
1071  case T_HashJoin:
1072  plan = (Plan *) create_hashjoin_plan(root,
1073  (HashPath *) best_path);
1074  break;
1075  case T_NestLoop:
1076  plan = (Plan *) create_nestloop_plan(root,
1077  (NestPath *) best_path);
1078  break;
1079  default:
1080  elog(ERROR, "unrecognized node type: %d",
1081  (int) best_path->path.pathtype);
1082  plan = NULL; /* keep compiler quiet */
1083  break;
1084  }
1085 
1086  /*
1087  * If there are any pseudoconstant clauses attached to this node, insert a
1088  * gating Result node that evaluates the pseudoconstants as one-time
1089  * quals.
1090  */
1091  gating_clauses = get_gating_quals(root, best_path->joinrestrictinfo);
1092  if (gating_clauses)
1093  plan = create_gating_plan(root, (Path *) best_path, plan,
1094  gating_clauses);
1095 
1096 #ifdef NOT_USED
1097 
1098  /*
1099  * * Expensive function pullups may have pulled local predicates * into
1100  * this path node. Put them in the qpqual of the plan node. * JMH,
1101  * 6/15/92
1102  */
1103  if (get_loc_restrictinfo(best_path) != NIL)
1104  set_qpqual((Plan) plan,
1105  list_concat(get_qpqual((Plan) plan),
1106  get_actual_clauses(get_loc_restrictinfo(best_path))));
1107 #endif
1108 
1109  return plan;
1110 }
1111 
1112 /*
1113  * mark_async_capable_plan
1114  * Check whether the Plan node created from a Path node is async-capable,
1115  * and if so, mark the Plan node as such and return true, otherwise
1116  * return false.
1117  */
1118 static bool
1119 mark_async_capable_plan(Plan *plan, Path *path)
1120 {
1121  switch (nodeTag(path))
1122  {
1123  case T_SubqueryScanPath:
1124  {
1125  SubqueryScan *scan_plan = (SubqueryScan *) plan;
1126 
1127  /*
1128  * If the generated plan node includes a gating Result node,
1129  * we can't execute it asynchronously.
1130  */
1131  if (IsA(plan, Result))
1132  return false;
1133 
1134  /*
1135  * If a SubqueryScan node atop of an async-capable plan node
1136  * is deletable, consider it as async-capable.
1137  */
1138  if (trivial_subqueryscan(scan_plan) &&
1139  mark_async_capable_plan(scan_plan->subplan,
1140  ((SubqueryScanPath *) path)->subpath))
1141  break;
1142  return false;
1143  }
1144  case T_ForeignPath:
1145  {
1146  FdwRoutine *fdwroutine = path->parent->fdwroutine;
1147 
1148  /*
1149  * If the generated plan node includes a gating Result node,
1150  * we can't execute it asynchronously.
1151  */
1152  if (IsA(plan, Result))
1153  return false;
1154 
1155  Assert(fdwroutine != NULL);
1156  if (fdwroutine->IsForeignPathAsyncCapable != NULL &&
1157  fdwroutine->IsForeignPathAsyncCapable((ForeignPath *) path))
1158  break;
1159  return false;
1160  }
1161  case T_ProjectionPath:
1162 
1163  /*
1164  * If the generated plan node includes a Result node for the
1165  * projection, we can't execute it asynchronously.
1166  */
1167  if (IsA(plan, Result))
1168  return false;
1169 
1170  /*
1171  * create_projection_plan() would have pulled up the subplan, so
1172  * check the capability using the subpath.
1173  */
1174  if (mark_async_capable_plan(plan,
1175  ((ProjectionPath *) path)->subpath))
1176  return true;
1177  return false;
1178  default:
1179  return false;
1180  }
1181 
1182  plan->async_capable = true;
1183 
1184  return true;
1185 }
1186 
1187 /*
1188  * create_append_plan
1189  * Create an Append plan for 'best_path' and (recursively) plans
1190  * for its subpaths.
1191  *
1192  * Returns a Plan node.
1193  */
1194 static Plan *
1195 create_append_plan(PlannerInfo *root, AppendPath *best_path, int flags)
1196 {
1197  Append *plan;
1198  List *tlist = build_path_tlist(root, &best_path->path);
1199  int orig_tlist_length = list_length(tlist);
1200  bool tlist_was_changed = false;
1201  List *pathkeys = best_path->path.pathkeys;
1202  List *subplans = NIL;
1203  ListCell *subpaths;
1204  int nasyncplans = 0;
1205  RelOptInfo *rel = best_path->path.parent;
1206  PartitionPruneInfo *partpruneinfo = NULL;
1207  int nodenumsortkeys = 0;
1208  AttrNumber *nodeSortColIdx = NULL;
1209  Oid *nodeSortOperators = NULL;
1210  Oid *nodeCollations = NULL;
1211  bool *nodeNullsFirst = NULL;
1212  bool consider_async = false;
1213 
1214  /*
1215  * The subpaths list could be empty, if every child was proven empty by
1216  * constraint exclusion. In that case generate a dummy plan that returns
1217  * no rows.
1218  *
1219  * Note that an AppendPath with no members is also generated in certain
1220  * cases where there was no appending construct at all, but we know the
1221  * relation is empty (see set_dummy_rel_pathlist and mark_dummy_rel).
1222  */
1223  if (best_path->subpaths == NIL)
1224  {
1225  /* Generate a Result plan with constant-FALSE gating qual */
1226  Plan *plan;
1227 
1228  plan = (Plan *) make_result(tlist,
1229  (Node *) list_make1(makeBoolConst(false,
1230  false)),
1231  NULL);
1232 
1233  copy_generic_path_info(plan, (Path *) best_path);
1234 
1235  return plan;
1236  }
1237 
1238  /*
1239  * Otherwise build an Append plan. Note that if there's just one child,
1240  * the Append is pretty useless; but we wait till setrefs.c to get rid of
1241  * it. Doing so here doesn't work because the varno of the child scan
1242  * plan won't match the parent-rel Vars it'll be asked to emit.
1243  *
1244  * We don't have the actual creation of the Append node split out into a
1245  * separate make_xxx function. This is because we want to run
1246  * prepare_sort_from_pathkeys on it before we do so on the individual
1247  * child plans, to make cross-checking the sort info easier.
1248  */
1249  plan = makeNode(Append);
1250  plan->plan.targetlist = tlist;
1251  plan->plan.qual = NIL;
1252  plan->plan.lefttree = NULL;
1253  plan->plan.righttree = NULL;
1254  plan->apprelids = rel->relids;
1255 
1256  if (pathkeys != NIL)
1257  {
1258  /*
1259  * Compute sort column info, and adjust the Append's tlist as needed.
1260  * Because we pass adjust_tlist_in_place = true, we may ignore the
1261  * function result; it must be the same plan node. However, we then
1262  * need to detect whether any tlist entries were added.
1263  */
1264  (void) prepare_sort_from_pathkeys((Plan *) plan, pathkeys,
1265  best_path->path.parent->relids,
1266  NULL,
1267  true,
1268  &nodenumsortkeys,
1269  &nodeSortColIdx,
1270  &nodeSortOperators,
1271  &nodeCollations,
1272  &nodeNullsFirst);
1273  tlist_was_changed = (orig_tlist_length != list_length(plan->plan.targetlist));
1274  }
1275 
1276  /* If appropriate, consider async append */
1277  consider_async = (enable_async_append && pathkeys == NIL &&
1278  !best_path->path.parallel_safe &&
1279  list_length(best_path->subpaths) > 1);
1280 
1281  /* Build the plan for each child */
1282  foreach(subpaths, best_path->subpaths)
1283  {
1284  Path *subpath = (Path *) lfirst(subpaths);
1285  Plan *subplan;
1286 
1287  /* Must insist that all children return the same tlist */
1288  subplan = create_plan_recurse(root, subpath, CP_EXACT_TLIST);
1289 
1290  /*
1291  * For ordered Appends, we must insert a Sort node if subplan isn't
1292  * sufficiently ordered.
1293  */
1294  if (pathkeys != NIL)
1295  {
1296  int numsortkeys;
1297  AttrNumber *sortColIdx;
1298  Oid *sortOperators;
1299  Oid *collations;
1300  bool *nullsFirst;
1301 
1302  /*
1303  * Compute sort column info, and adjust subplan's tlist as needed.
1304  * We must apply prepare_sort_from_pathkeys even to subplans that
1305  * don't need an explicit sort, to make sure they are returning
1306  * the same sort key columns the Append expects.
1307  */
1308  subplan = prepare_sort_from_pathkeys(subplan, pathkeys,
1309  subpath->parent->relids,
1310  nodeSortColIdx,
1311  false,
1312  &numsortkeys,
1313  &sortColIdx,
1314  &sortOperators,
1315  &collations,
1316  &nullsFirst);
1317 
1318  /*
1319  * Check that we got the same sort key information. We just
1320  * Assert that the sortops match, since those depend only on the
1321  * pathkeys; but it seems like a good idea to check the sort
1322  * column numbers explicitly, to ensure the tlists match up.
1323  */
1324  Assert(numsortkeys == nodenumsortkeys);
1325  if (memcmp(sortColIdx, nodeSortColIdx,
1326  numsortkeys * sizeof(AttrNumber)) != 0)
1327  elog(ERROR, "Append child's targetlist doesn't match Append");
1328  Assert(memcmp(sortOperators, nodeSortOperators,
1329  numsortkeys * sizeof(Oid)) == 0);
1330  Assert(memcmp(collations, nodeCollations,
1331  numsortkeys * sizeof(Oid)) == 0);
1332  Assert(memcmp(nullsFirst, nodeNullsFirst,
1333  numsortkeys * sizeof(bool)) == 0);
1334 
1335  /* Now, insert a Sort node if subplan isn't sufficiently ordered */
1336  if (!pathkeys_contained_in(pathkeys, subpath->pathkeys))
1337  {
1338  Sort *sort = make_sort(subplan, numsortkeys,
1339  sortColIdx, sortOperators,
1340  collations, nullsFirst);
1341 
1342  label_sort_with_costsize(root, sort, best_path->limit_tuples);
1343  subplan = (Plan *) sort;
1344  }
1345  }
1346 
1347  /* If needed, check to see if subplan can be executed asynchronously */
1348  if (consider_async && mark_async_capable_plan(subplan, subpath))
1349  {
1350  Assert(subplan->async_capable);
1351  ++nasyncplans;
1352  }
1353 
1354  subplans = lappend(subplans, subplan);
1355  }
1356 
1357  /*
1358  * If any quals exist, they may be useful to perform further partition
1359  * pruning during execution. Gather information needed by the executor to
1360  * do partition pruning.
1361  */
1362  if (enable_partition_pruning)
1363  {
1364  List *prunequal;
1365 
1366  prunequal = extract_actual_clauses(rel->baserestrictinfo, false);
1367 
1368  if (best_path->path.param_info)
1369  {
1370  List *prmquals = best_path->path.param_info->ppi_clauses;
1371 
1372  prmquals = extract_actual_clauses(prmquals, false);
1373  prmquals = (List *) replace_nestloop_params(root,
1374  (Node *) prmquals);
1375 
1376  prunequal = list_concat(prunequal, prmquals);
1377  }
1378 
1379  if (prunequal != NIL)
1380  partpruneinfo =
1381  make_partition_pruneinfo(root, rel,
1382  best_path->subpaths,
1383  prunequal);
1384  }
1385 
1386  plan->appendplans = subplans;
1387  plan->nasyncplans = nasyncplans;
1388  plan->first_partial_plan = best_path->first_partial_path;
1389  plan->part_prune_info = partpruneinfo;
1390 
1391  copy_generic_path_info(&plan->plan, (Path *) best_path);
1392 
1393  /*
1394  * If prepare_sort_from_pathkeys added sort columns, but we were told to
1395  * produce either the exact tlist or a narrow tlist, we should get rid of
1396  * the sort columns again. We must inject a projection node to do so.
1397  */
1398  if (tlist_was_changed && (flags & (CP_EXACT_TLIST | CP_SMALL_TLIST)))
1399  {
1400  tlist = list_truncate(list_copy(plan->plan.targetlist),
1401  orig_tlist_length);
1402  return inject_projection_plan((Plan *) plan, tlist,
1403  plan->plan.parallel_safe);
1404  }
1405  else
1406  return (Plan *) plan;
1407 }
1408 
1409 /*
1410  * create_merge_append_plan
1411  * Create a MergeAppend plan for 'best_path' and (recursively) plans
1412  * for its subpaths.
1413  *
1414  * Returns a Plan node.
1415  */
1416 static Plan *
1417 create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path,
1418  int flags)
1419 {
1420  MergeAppend *node = makeNode(MergeAppend);
1421  Plan *plan = &node->plan;
1422  List *tlist = build_path_tlist(root, &best_path->path);
1423  int orig_tlist_length = list_length(tlist);
1424  bool tlist_was_changed;
1425  List *pathkeys = best_path->path.pathkeys;
1426  List *subplans = NIL;
1427  ListCell *subpaths;
1428  RelOptInfo *rel = best_path->path.parent;
1429  PartitionPruneInfo *partpruneinfo = NULL;
1430 
1431  /*
1432  * We don't have the actual creation of the MergeAppend node split out
1433  * into a separate make_xxx function. This is because we want to run
1434  * prepare_sort_from_pathkeys on it before we do so on the individual
1435  * child plans, to make cross-checking the sort info easier.
1436  */
1437  copy_generic_path_info(plan, (Path *) best_path);
1438  plan->targetlist = tlist;
1439  plan->qual = NIL;
1440  plan->lefttree = NULL;
1441  plan->righttree = NULL;
1442  node->apprelids = rel->relids;
1443 
1444  /*
1445  * Compute sort column info, and adjust MergeAppend's tlist as needed.
1446  * Because we pass adjust_tlist_in_place = true, we may ignore the
1447  * function result; it must be the same plan node. However, we then need
1448  * to detect whether any tlist entries were added.
1449  */
1450  (void) prepare_sort_from_pathkeys(plan, pathkeys,
1451  best_path->path.parent->relids,
1452  NULL,
1453  true,
1454  &node->numCols,
1455  &node->sortColIdx,
1456  &node->sortOperators,
1457  &node->collations,
1458  &node->nullsFirst);
1459  tlist_was_changed = (orig_tlist_length != list_length(plan->targetlist));
1460 
1461  /*
1462  * Now prepare the child plans. We must apply prepare_sort_from_pathkeys
1463  * even to subplans that don't need an explicit sort, to make sure they
1464  * are returning the same sort key columns the MergeAppend expects.
1465  */
1466  foreach(subpaths, best_path->subpaths)
1467  {
1468  Path *subpath = (Path *) lfirst(subpaths);
1469  Plan *subplan;
1470  int numsortkeys;
1471  AttrNumber *sortColIdx;
1472  Oid *sortOperators;
1473  Oid *collations;
1474  bool *nullsFirst;
1475 
1476  /* Build the child plan */
1477  /* Must insist that all children return the same tlist */
1478  subplan = create_plan_recurse(root, subpath, CP_EXACT_TLIST);
1479 
1480  /* Compute sort column info, and adjust subplan's tlist as needed */
1481  subplan = prepare_sort_from_pathkeys(subplan, pathkeys,
1482  subpath->parent->relids,
1483  node->sortColIdx,
1484  false,
1485  &numsortkeys,
1486  &sortColIdx,
1487  &sortOperators,
1488  &collations,
1489  &nullsFirst);
1490 
1491  /*
1492  * Check that we got the same sort key information. We just Assert
1493  * that the sortops match, since those depend only on the pathkeys;
1494  * but it seems like a good idea to check the sort column numbers
1495  * explicitly, to ensure the tlists really do match up.
1496  */
1497  Assert(numsortkeys == node->numCols);
1498  if (memcmp(sortColIdx, node->sortColIdx,
1499  numsortkeys * sizeof(AttrNumber)) != 0)
1500  elog(ERROR, "MergeAppend child's targetlist doesn't match MergeAppend");
1501  Assert(memcmp(sortOperators, node->sortOperators,
1502  numsortkeys * sizeof(Oid)) == 0);
1503  Assert(memcmp(collations, node->collations,
1504  numsortkeys * sizeof(Oid)) == 0);
1505  Assert(memcmp(nullsFirst, node->nullsFirst,
1506  numsortkeys * sizeof(bool)) == 0);
1507 
1508  /* Now, insert a Sort node if subplan isn't sufficiently ordered */
1509  if (!pathkeys_contained_in(pathkeys, subpath->pathkeys))
1510  {
1511  Sort *sort = make_sort(subplan, numsortkeys,
1512  sortColIdx, sortOperators,
1513  collations, nullsFirst);
1514 
1515  label_sort_with_costsize(root, sort, best_path->limit_tuples);
1516  subplan = (Plan *) sort;
1517  }
1518 
1519  subplans = lappend(subplans, subplan);
1520  }
1521 
1522  /*
1523  * If any quals exist, they may be useful to perform further partition
1524  * pruning during execution. Gather information needed by the executor to
1525  * do partition pruning.
1526  */
1527  if (enable_partition_pruning)
1528  {
1529  List *prunequal;
1530 
1531  prunequal = extract_actual_clauses(rel->baserestrictinfo, false);
1532 
1533  if (best_path->path.param_info)
1534  {
1535  List *prmquals = best_path->path.param_info->ppi_clauses;
1536 
1537  prmquals = extract_actual_clauses(prmquals, false);
1538  prmquals = (List *) replace_nestloop_params(root,
1539  (Node *) prmquals);
1540 
1541  prunequal = list_concat(prunequal, prmquals);
1542  }
1543 
1544  if (prunequal != NIL)
1545  partpruneinfo = make_partition_pruneinfo(root, rel,
1546  best_path->subpaths,
1547  prunequal);
1548  }
1549 
1550  node->mergeplans = subplans;
1551  node->part_prune_info = partpruneinfo;
1552 
1553  /*
1554  * If prepare_sort_from_pathkeys added sort columns, but we were told to
1555  * produce either the exact tlist or a narrow tlist, we should get rid of
1556  * the sort columns again. We must inject a projection node to do so.
1557  */
1558  if (tlist_was_changed && (flags & (CP_EXACT_TLIST | CP_SMALL_TLIST)))
1559  {
1560  tlist = list_truncate(list_copy(plan->targetlist), orig_tlist_length);
1561  return inject_projection_plan(plan, tlist, plan->parallel_safe);
1562  }
1563  else
1564  return plan;
1565 }
1566 
1567 /*
1568  * create_group_result_plan
1569  * Create a Result plan for 'best_path'.
1570  * This is only used for degenerate grouping cases.
1571  *
1572  * Returns a Plan node.
1573  */
1574 static Result *
1575 create_group_result_plan(PlannerInfo *root, GroupResultPath *best_path)
1576 {
1577  Result *plan;
1578  List *tlist;
1579  List *quals;
1580 
1581  tlist = build_path_tlist(root, &best_path->path);
1582 
1583  /* best_path->quals is just bare clauses */
1584  quals = order_qual_clauses(root, best_path->quals);
1585 
1586  plan = make_result(tlist, (Node *) quals, NULL);
1587 
1588  copy_generic_path_info(&plan->plan, (Path *) best_path);
1589 
1590  return plan;
1591 }
1592 
1593 /*
1594  * create_project_set_plan
1595  * Create a ProjectSet plan for 'best_path'.
1596  *
1597  * Returns a Plan node.
1598  */
1599 static ProjectSet *
1600 create_project_set_plan(PlannerInfo *root, ProjectSetPath *best_path)
1601 {
1602  ProjectSet *plan;
1603  Plan *subplan;
1604  List *tlist;
1605 
1606  /* Since we intend to project, we don't need to constrain child tlist */
1607  subplan = create_plan_recurse(root, best_path->subpath, 0);
1608 
1609  tlist = build_path_tlist(root, &best_path->path);
1610 
1611  plan = make_project_set(tlist, subplan);
1612 
1613  copy_generic_path_info(&plan->plan, (Path *) best_path);
1614 
1615  return plan;
1616 }
1617 
1618 /*
1619  * create_material_plan
1620  * Create a Material plan for 'best_path' and (recursively) plans
1621  * for its subpaths.
1622  *
1623  * Returns a Plan node.
1624  */
1625 static Material *
1626 create_material_plan(PlannerInfo *root, MaterialPath *best_path, int flags)
1627 {
1628  Material *plan;
1629  Plan *subplan;
1630 
1631  /*
1632  * We don't want any excess columns in the materialized tuples, so request
1633  * a smaller tlist. Otherwise, since Material doesn't project, tlist
1634  * requirements pass through.
1635  */
1636  subplan = create_plan_recurse(root, best_path->subpath,
1637  flags | CP_SMALL_TLIST);
1638 
1639  plan = make_material(subplan);
1640 
1641  copy_generic_path_info(&plan->plan, (Path *) best_path);
1642 
1643  return plan;
1644 }
1645 
1646 /*
1647  * create_memoize_plan
1648  * Create a Memoize plan for 'best_path' and (recursively) plans for its
1649  * subpaths.
1650  *
1651  * Returns a Plan node.
1652  */
1653 static Memoize *
1654 create_memoize_plan(PlannerInfo *root, MemoizePath *best_path, int flags)
1655 {
1656  Memoize *plan;
1657  Bitmapset *keyparamids;
1658  Plan *subplan;
1659  Oid *operators;
1660  Oid *collations;
1661  List *param_exprs = NIL;
1662  ListCell *lc;
1663  ListCell *lc2;
1664  int nkeys;
1665  int i;
1666 
1667  subplan = create_plan_recurse(root, best_path->subpath,
1668  flags | CP_SMALL_TLIST);
1669 
1670  param_exprs = (List *) replace_nestloop_params(root, (Node *)
1671  best_path->param_exprs);
1672 
1673  nkeys = list_length(param_exprs);
1674  Assert(nkeys > 0);
1675  operators = palloc(nkeys * sizeof(Oid));
1676  collations = palloc(nkeys * sizeof(Oid));
1677 
1678  i = 0;
1679  forboth(lc, param_exprs, lc2, best_path->hash_operators)
1680  {
1681  Expr *param_expr = (Expr *) lfirst(lc);
1682  Oid opno = lfirst_oid(lc2);
1683 
1684  operators[i] = opno;
1685  collations[i] = exprCollation((Node *) param_expr);
1686  i++;
1687  }
1688 
1689  keyparamids = pull_paramids((Expr *) param_exprs);
1690 
1691  plan = make_memoize(subplan, operators, collations, param_exprs,
1692  best_path->singlerow, best_path->binary_mode,
1693  best_path->est_entries, keyparamids);
1694 
1695  copy_generic_path_info(&plan->plan, (Path *) best_path);
1696 
1697  return plan;
1698 }
1699 
1700 /*
1701  * create_unique_plan
1702  * Create a Unique plan for 'best_path' and (recursively) plans
1703  * for its subpaths.
1704  *
1705  * Returns a Plan node.
1706  */
1707 static Plan *
1708 create_unique_plan(PlannerInfo *root, UniquePath *best_path, int flags)
1709 {
1710  Plan *plan;
1711  Plan *subplan;
1712  List *in_operators;
1713  List *uniq_exprs;
1714  List *newtlist;
1715  int nextresno;
1716  bool newitems;
1717  int numGroupCols;
1718  AttrNumber *groupColIdx;
1719  Oid *groupCollations;
1720  int groupColPos;
1721  ListCell *l;
1722 
1723  /* Unique doesn't project, so tlist requirements pass through */
1724  subplan = create_plan_recurse(root, best_path->subpath, flags);
1725 
1726  /* Done if we don't need to do any actual unique-ifying */
1727  if (best_path->umethod == UNIQUE_PATH_NOOP)
1728  return subplan;
1729 
1730  /*
1731  * As constructed, the subplan has a "flat" tlist containing just the Vars
1732  * needed here and at upper levels. The values we are supposed to
1733  * unique-ify may be expressions in these variables. We have to add any
1734  * such expressions to the subplan's tlist.
1735  *
1736  * The subplan may have a "physical" tlist if it is a simple scan plan. If
1737  * we're going to sort, this should be reduced to the regular tlist, so
1738  * that we don't sort more data than we need to. For hashing, the tlist
1739  * should be left as-is if we don't need to add any expressions; but if we
1740  * do have to add expressions, then a projection step will be needed at
1741  * runtime anyway, so we may as well remove unneeded items. Therefore
1742  * newtlist starts from build_path_tlist() not just a copy of the
1743  * subplan's tlist; and we don't install it into the subplan unless we are
1744  * sorting or stuff has to be added.
1745  */
1746  in_operators = best_path->in_operators;
1747  uniq_exprs = best_path->uniq_exprs;
1748 
1749  /* initialize modified subplan tlist as just the "required" vars */
1750  newtlist = build_path_tlist(root, &best_path->path);
1751  nextresno = list_length(newtlist) + 1;
1752  newitems = false;
1753 
1754  foreach(l, uniq_exprs)
1755  {
1756  Expr *uniqexpr = lfirst(l);
1757  TargetEntry *tle;
1758 
1759  tle = tlist_member(uniqexpr, newtlist);
1760  if (!tle)
1761  {
1762  tle = makeTargetEntry((Expr *) uniqexpr,
1763  nextresno,
1764  NULL,
1765  false);
1766  newtlist = lappend(newtlist, tle);
1767  nextresno++;
1768  newitems = true;
1769  }
1770  }
1771 
1772  /* Use change_plan_targetlist in case we need to insert a Result node */
1773  if (newitems || best_path->umethod == UNIQUE_PATH_SORT)
1774  subplan = change_plan_targetlist(subplan, newtlist,
1775  best_path->path.parallel_safe);
1776 
1777  /*
1778  * Build control information showing which subplan output columns are to
1779  * be examined by the grouping step. Unfortunately we can't merge this
1780  * with the previous loop, since we didn't then know which version of the
1781  * subplan tlist we'd end up using.
1782  */
1783  newtlist = subplan->targetlist;
1784  numGroupCols = list_length(uniq_exprs);
1785  groupColIdx = (AttrNumber *) palloc(numGroupCols * sizeof(AttrNumber));
1786  groupCollations = (Oid *) palloc(numGroupCols * sizeof(Oid));
1787 
1788  groupColPos = 0;
1789  foreach(l, uniq_exprs)
1790  {
1791  Expr *uniqexpr = lfirst(l);
1792  TargetEntry *tle;
1793 
1794  tle = tlist_member(uniqexpr, newtlist);
1795  if (!tle) /* shouldn't happen */
1796  elog(ERROR, "failed to find unique expression in subplan tlist");
1797  groupColIdx[groupColPos] = tle->resno;
1798  groupCollations[groupColPos] = exprCollation((Node *) tle->expr);
1799  groupColPos++;
1800  }
1801 
1802  if (best_path->umethod == UNIQUE_PATH_HASH)
1803  {
1804  Oid *groupOperators;
1805 
1806  /*
1807  * Get the hashable equality operators for the Agg node to use.
1808  * Normally these are the same as the IN clause operators, but if
1809  * those are cross-type operators then the equality operators are the
1810  * ones for the IN clause operators' RHS datatype.
1811  */
1812  groupOperators = (Oid *) palloc(numGroupCols * sizeof(Oid));
1813  groupColPos = 0;
1814  foreach(l, in_operators)
1815  {
1816  Oid in_oper = lfirst_oid(l);
1817  Oid eq_oper;
1818 
1819  if (!get_compatible_hash_operators(in_oper, NULL, &eq_oper))
1820  elog(ERROR, "could not find compatible hash operator for operator %u",
1821  in_oper);
1822  groupOperators[groupColPos++] = eq_oper;
1823  }
1824 
1825  /*
1826  * Since the Agg node is going to project anyway, we can give it the
1827  * minimum output tlist, without any stuff we might have added to the
1828  * subplan tlist.
1829  */
1830  plan = (Plan *) make_agg(build_path_tlist(root, &best_path->path),
1831  NIL,
1832  AGG_HASHED,
1833  AGGSPLIT_SIMPLE,
1834  numGroupCols,
1835  groupColIdx,
1836  groupOperators,
1837  groupCollations,
1838  NIL,
1839  NIL,
1840  best_path->path.rows,
1841  0,
1842  subplan);
1843  }
1844  else
1845  {
1846  List *sortList = NIL;
1847  Sort *sort;
1848 
1849  /* Create an ORDER BY list to sort the input compatibly */
1850  groupColPos = 0;
1851  foreach(l, in_operators)
1852  {
1853  Oid in_oper = lfirst_oid(l);
1854  Oid sortop;
1855  Oid eqop;
1856  TargetEntry *tle;
1857  SortGroupClause *sortcl;
1858 
1859  sortop = get_ordering_op_for_equality_op(in_oper, false);
1860  if (!OidIsValid(sortop)) /* shouldn't happen */
1861  elog(ERROR, "could not find ordering operator for equality operator %u",
1862  in_oper);
1863 
1864  /*
1865  * The Unique node will need equality operators. Normally these
1866  * are the same as the IN clause operators, but if those are
1867  * cross-type operators then the equality operators are the ones
1868  * for the IN clause operators' RHS datatype.
1869  */
1870  eqop = get_equality_op_for_ordering_op(sortop, NULL);
1871  if (!OidIsValid(eqop)) /* shouldn't happen */
1872  elog(ERROR, "could not find equality operator for ordering operator %u",
1873  sortop);
1874 
1875  tle = get_tle_by_resno(subplan->targetlist,
1876  groupColIdx[groupColPos]);
1877  Assert(tle != NULL);
1878 
1879  sortcl = makeNode(SortGroupClause);
1880  sortcl->tleSortGroupRef = assignSortGroupRef(tle,
1881  subplan->targetlist);
1882  sortcl->eqop = eqop;
1883  sortcl->sortop = sortop;
1884  sortcl->nulls_first = false;
1885  sortcl->hashable = false; /* no need to make this accurate */
1886  sortList = lappend(sortList, sortcl);
1887  groupColPos++;
1888  }
1889  sort = make_sort_from_sortclauses(sortList, subplan);
1890  label_sort_with_costsize(root, sort, -1.0);
1891  plan = (Plan *) make_unique_from_sortclauses((Plan *) sort, sortList);
1892  }
1893 
1894  /* Copy cost data from Path to Plan */
1895  copy_generic_path_info(plan, &best_path->path);
1896 
1897  return plan;
1898 }
1899 
1900 /*
1901  * create_gather_plan
1902  *
1903  * Create a Gather plan for 'best_path' and (recursively) plans
1904  * for its subpaths.
1905  */
1906 static Gather *
1907 create_gather_plan(PlannerInfo *root, GatherPath *best_path)
1908 {
1909  Gather *gather_plan;
1910  Plan *subplan;
1911  List *tlist;
1912 
1913  /*
1914  * Push projection down to the child node. That way, the projection work
1915  * is parallelized, and there can be no system columns in the result (they
1916  * can't travel through a tuple queue because it uses MinimalTuple
1917  * representation).
1918  */
1919  subplan = create_plan_recurse(root, best_path->subpath, CP_EXACT_TLIST);
1920 
1921  tlist = build_path_tlist(root, &best_path->path);
1922 
1923  gather_plan = make_gather(tlist,
1924  NIL,
1925  best_path->num_workers,
1926  assign_special_exec_param(root),
1927  best_path->single_copy,
1928  subplan);
1929 
1930  copy_generic_path_info(&gather_plan->plan, &best_path->path);
1931 
1932  /* use parallel mode for parallel plans. */
1933  root->glob->parallelModeNeeded = true;
1934 
1935  return gather_plan;
1936 }
1937 
1938 /*
1939  * create_gather_merge_plan
1940  *
1941  * Create a Gather Merge plan for 'best_path' and (recursively)
1942  * plans for its subpaths.
1943  */
1944 static GatherMerge *
1945 create_gather_merge_plan(PlannerInfo *root, GatherMergePath *best_path)
1946 {
1947  GatherMerge *gm_plan;
1948  Plan *subplan;
1949  List *pathkeys = best_path->path.pathkeys;
1950  List *tlist = build_path_tlist(root, &best_path->path);
1951 
1952  /* As with Gather, project away columns in the workers. */
1953  subplan = create_plan_recurse(root, best_path->subpath, CP_EXACT_TLIST);
1954 
1955  /* Create a shell for a GatherMerge plan. */
1956  gm_plan = makeNode(GatherMerge);
1957  gm_plan->plan.targetlist = tlist;
1958  gm_plan->num_workers = best_path->num_workers;
1959  copy_generic_path_info(&gm_plan->plan, &best_path->path);
1960 
1961  /* Assign the rescan Param. */
1962  gm_plan->rescan_param = assign_special_exec_param(root);
1963 
1964  /* Gather Merge is pointless with no pathkeys; use Gather instead. */
1965  Assert(pathkeys != NIL);
1966 
1967  /* Compute sort column info, and adjust subplan's tlist as needed */
1968  subplan = prepare_sort_from_pathkeys(subplan, pathkeys,
1969  best_path->subpath->parent->relids,
1970  gm_plan->sortColIdx,
1971  false,
1972  &gm_plan->numCols,
1973  &gm_plan->sortColIdx,
1974  &gm_plan->sortOperators,
1975  &gm_plan->collations,
1976  &gm_plan->nullsFirst);
1977 
1978 
1979  /*
1980  * All gather merge paths should have already guaranteed the necessary
1981  * sort order either by adding an explicit sort node or by using presorted
1982  * input. We can't simply add a sort here on additional pathkeys, because
1983  * we can't guarantee the sort would be safe. For example, expressions may
1984  * be volatile or otherwise parallel unsafe.
1985  */
1986  if (!pathkeys_contained_in(pathkeys, best_path->subpath->pathkeys))
1987  elog(ERROR, "gather merge input not sufficiently sorted");
1988 
1989  /* Now insert the subplan under GatherMerge. */
1990  gm_plan->plan.lefttree = subplan;
1991 
1992  /* use parallel mode for parallel plans. */
1993  root->glob->parallelModeNeeded = true;
1994 
1995  return gm_plan;
1996 }
1997 
1998 /*
1999  * create_projection_plan
2000  *
2001  * Create a plan tree to do a projection step and (recursively) plans
2002  * for its subpaths. We may need a Result node for the projection,
2003  * but sometimes we can just let the subplan do the work.
2004  */
2005 static Plan *
2006 create_projection_plan(PlannerInfo *root, ProjectionPath *best_path, int flags)
2007 {
2008  Plan *plan;
2009  Plan *subplan;
2010  List *tlist;
2011  bool needs_result_node = false;
2012 
2013  /*
2014  * Convert our subpath to a Plan and determine whether we need a Result
2015  * node.
2016  *
2017  * In most cases where we don't need to project, creation_projection_path
2018  * will have set dummypp, but not always. First, some createplan.c
2019  * routines change the tlists of their nodes. (An example is that
2020  * create_merge_append_plan might add resjunk sort columns to a
2021  * MergeAppend.) Second, create_projection_path has no way of knowing
2022  * what path node will be placed on top of the projection path and
2023  * therefore can't predict whether it will require an exact tlist. For
2024  * both of these reasons, we have to recheck here.
2025  */
2026  if (use_physical_tlist(root, &best_path->path, flags))
2027  {
2028  /*
2029  * Our caller doesn't really care what tlist we return, so we don't
2030  * actually need to project. However, we may still need to ensure
2031  * proper sortgroupref labels, if the caller cares about those.
2032  */
2033  subplan = create_plan_recurse(root, best_path->subpath, 0);
2034  tlist = subplan->targetlist;
2035  if (flags & CP_LABEL_TLIST)
2036  apply_pathtarget_labeling_to_tlist(tlist,
2037  best_path->path.pathtarget);
2038  }
2039  else if (is_projection_capable_path(best_path->subpath))
2040  {
2041  /*
2042  * Our caller requires that we return the exact tlist, but no separate
2043  * result node is needed because the subpath is projection-capable.
2044  * Tell create_plan_recurse that we're going to ignore the tlist it
2045  * produces.
2046  */
2047  subplan = create_plan_recurse(root, best_path->subpath,
2048  CP_IGNORE_TLIST);
2049  Assert(is_projection_capable_plan(subplan));
2050  tlist = build_path_tlist(root, &best_path->path);
2051  }
2052  else
2053  {
2054  /*
2055  * It looks like we need a result node, unless by good fortune the
2056  * requested tlist is exactly the one the child wants to produce.
2057  */
2058  subplan = create_plan_recurse(root, best_path->subpath, 0);
2059  tlist = build_path_tlist(root, &best_path->path);
2060  needs_result_node = !tlist_same_exprs(tlist, subplan->targetlist);
2061  }
2062 
2063  /*
2064  * If we make a different decision about whether to include a Result node
2065  * than create_projection_path did, we'll have made slightly wrong cost
2066  * estimates; but label the plan with the cost estimates we actually used,
2067  * not "corrected" ones. (XXX this could be cleaned up if we moved more
2068  * of the sortcolumn setup logic into Path creation, but that would add
2069  * expense to creating Paths we might end up not using.)
2070  */
2071  if (!needs_result_node)
2072  {
2073  /* Don't need a separate Result, just assign tlist to subplan */
2074  plan = subplan;
2075  plan->targetlist = tlist;
2076 
2077  /* Label plan with the estimated costs we actually used */
2078  plan->startup_cost = best_path->path.startup_cost;
2079  plan->total_cost = best_path->path.total_cost;
2080  plan->plan_rows = best_path->path.rows;
2081  plan->plan_width = best_path->path.pathtarget->width;
2082  plan->parallel_safe = best_path->path.parallel_safe;
2083  /* ... but don't change subplan's parallel_aware flag */
2084  }
2085  else
2086  {
2087  /* We need a Result node */
2088  plan = (Plan *) make_result(tlist, NULL, subplan);
2089 
2090  copy_generic_path_info(plan, (Path *) best_path);
2091  }
2092 
2093  return plan;
2094 }
2095 
2096 /*
2097  * inject_projection_plan
2098  * Insert a Result node to do a projection step.
2099  *
2100  * This is used in a few places where we decide on-the-fly that we need a
2101  * projection step as part of the tree generated for some Path node.
2102  * We should try to get rid of this in favor of doing it more honestly.
2103  *
2104  * One reason it's ugly is we have to be told the right parallel_safe marking
2105  * to apply (since the tlist might be unsafe even if the child plan is safe).
2106  */
2107 static Plan *
2108 inject_projection_plan(Plan *subplan, List *tlist, bool parallel_safe)
2109 {
2110  Plan *plan;
2111 
2112  plan = (Plan *) make_result(tlist, NULL, subplan);
2113 
2114  /*
2115  * In principle, we should charge tlist eval cost plus cpu_per_tuple per
2116  * row for the Result node. But the former has probably been factored in
2117  * already and the latter was not accounted for during Path construction,
2118  * so being formally correct might just make the EXPLAIN output look less
2119  * consistent not more so. Hence, just copy the subplan's cost.
2120  */
2121  copy_plan_costsize(plan, subplan);
2122  plan->parallel_safe = parallel_safe;
2123 
2124  return plan;
2125 }
2126 
2127 /*
2128  * change_plan_targetlist
2129  * Externally available wrapper for inject_projection_plan.
2130  *
2131  * This is meant for use by FDW plan-generation functions, which might
2132  * want to adjust the tlist computed by some subplan tree. In general,
2133  * a Result node is needed to compute the new tlist, but we can optimize
2134  * some cases.
2135  *
2136  * In most cases, tlist_parallel_safe can just be passed as the parallel_safe
2137  * flag of the FDW's own Path node.
2138  */
2139 Plan *
2140 change_plan_targetlist(Plan *subplan, List *tlist, bool tlist_parallel_safe)
2141 {
2142  /*
2143  * If the top plan node can't do projections and its existing target list
2144  * isn't already what we need, we need to add a Result node to help it
2145  * along.
2146  */
2147  if (!is_projection_capable_plan(subplan) &&
2148  !tlist_same_exprs(tlist, subplan->targetlist))
2149  subplan = inject_projection_plan(subplan, tlist,
2150  subplan->parallel_safe &&
2151  tlist_parallel_safe);
2152  else
2153  {
2154  /* Else we can just replace the plan node's tlist */
2155  subplan->targetlist = tlist;
2156  subplan->parallel_safe &= tlist_parallel_safe;
2157  }
2158  return subplan;
2159 }
2160 
2161 /*
2162  * create_sort_plan
2163  *
2164  * Create a Sort plan for 'best_path' and (recursively) plans
2165  * for its subpaths.
2166  */
2167 static Sort *
2168 create_sort_plan(PlannerInfo *root, SortPath *best_path, int flags)
2169 {
2170  Sort *plan;
2171  Plan *subplan;
2172 
2173  /*
2174  * We don't want any excess columns in the sorted tuples, so request a
2175  * smaller tlist. Otherwise, since Sort doesn't project, tlist
2176  * requirements pass through.
2177  */
2178  subplan = create_plan_recurse(root, best_path->subpath,
2179  flags | CP_SMALL_TLIST);
2180 
2181  /*
2182  * make_sort_from_pathkeys indirectly calls find_ec_member_matching_expr,
2183  * which will ignore any child EC members that don't belong to the given
2184  * relids. Thus, if this sort path is based on a child relation, we must
2185  * pass its relids.
2186  */
2187  plan = make_sort_from_pathkeys(subplan, best_path->path.pathkeys,
2188  IS_OTHER_REL(best_path->subpath->parent) ?
2189  best_path->path.parent->relids : NULL);
2190 
2191  copy_generic_path_info(&plan->plan, (Path *) best_path);
2192 
2193  return plan;
2194 }
2195 
2196 /*
2197  * create_incrementalsort_plan
2198  *
2199  * Do the same as create_sort_plan, but create IncrementalSort plan.
2200  */
2201 static IncrementalSort *
2202 create_incrementalsort_plan(PlannerInfo *root, IncrementalSortPath *best_path,
2203  int flags)
2204 {
2205  IncrementalSort *plan;
2206  Plan *subplan;
2207 
2208  /* See comments in create_sort_plan() above */
2209  subplan = create_plan_recurse(root, best_path->spath.subpath,
2210  flags | CP_SMALL_TLIST);
2211  plan = make_incrementalsort_from_pathkeys(subplan,
2212  best_path->spath.path.pathkeys,
2213  IS_OTHER_REL(best_path->spath.subpath->parent) ?
2214  best_path->spath.path.parent->relids : NULL,
2215  best_path->nPresortedCols);
2216 
2217  copy_generic_path_info(&plan->sort.plan, (Path *) best_path);
2218 
2219  return plan;
2220 }
2221 
2222 /*
2223  * create_group_plan
2224  *
2225  * Create a Group plan for 'best_path' and (recursively) plans
2226  * for its subpaths.
2227  */
2228 static Group *
2229 create_group_plan(PlannerInfo *root, GroupPath *best_path)
2230 {
2231  Group *plan;
2232  Plan *subplan;
2233  List *tlist;
2234  List *quals;
2235 
2236  /*
2237  * Group can project, so no need to be terribly picky about child tlist,
2238  * but we do need grouping columns to be available
2239  */
2240  subplan = create_plan_recurse(root, best_path->subpath, CP_LABEL_TLIST);
2241 
2242  tlist = build_path_tlist(root, &best_path->path);
2243 
2244  quals = order_qual_clauses(root, best_path->qual);
2245 
2246  plan = make_group(tlist,
2247  quals,
2248  list_length(best_path->groupClause),
2249  extract_grouping_cols(best_path->groupClause,
2250  subplan->targetlist),
2251  extract_grouping_ops(best_path->groupClause),
2252  extract_grouping_collations(best_path->groupClause,
2253  subplan->targetlist),
2254  subplan);
2255 
2256  copy_generic_path_info(&plan->plan, (Path *) best_path);
2257 
2258  return plan;
2259 }
2260 
2261 /*
2262  * create_upper_unique_plan
2263  *
2264  * Create a Unique plan for 'best_path' and (recursively) plans
2265  * for its subpaths.
2266  */
2267 static Unique *
2268 create_upper_unique_plan(PlannerInfo *root, UpperUniquePath *best_path, int flags)
2269 {
2270  Unique *plan;
2271  Plan *subplan;
2272 
2273  /*
2274  * Unique doesn't project, so tlist requirements pass through; moreover we
2275  * need grouping columns to be labeled.
2276  */
2277  subplan = create_plan_recurse(root, best_path->subpath,
2278  flags | CP_LABEL_TLIST);
2279 
2280  plan = make_unique_from_pathkeys(subplan,
2281  best_path->path.pathkeys,
2282  best_path->numkeys);
2283 
2284  copy_generic_path_info(&plan->plan, (Path *) best_path);
2285 
2286  return plan;
2287 }
2288 
2289 /*
2290  * create_agg_plan
2291  *
2292  * Create an Agg plan for 'best_path' and (recursively) plans
2293  * for its subpaths.
2294  */
2295 static Agg *
2296 create_agg_plan(PlannerInfo *root, AggPath *best_path)
2297 {
2298  Agg *plan;
2299  Plan *subplan;
2300  List *tlist;
2301  List *quals;
2302 
2303  /*
2304  * Agg can project, so no need to be terribly picky about child tlist, but
2305  * we do need grouping columns to be available
2306  */
2307  subplan = create_plan_recurse(root, best_path->subpath, CP_LABEL_TLIST);
2308 
2309  tlist = build_path_tlist(root, &best_path->path);
2310 
2311  quals = order_qual_clauses(root, best_path->qual);
2312 
2313  plan = make_agg(tlist, quals,
2314  best_path->aggstrategy,
2315  best_path->aggsplit,
2316  list_length(best_path->groupClause),
2317  extract_grouping_cols(best_path->groupClause,
2318  subplan->targetlist),
2319  extract_grouping_ops(best_path->groupClause),
2320  extract_grouping_collations(best_path->groupClause,
2321  subplan->targetlist),
2322  NIL,
2323  NIL,
2324  best_path->numGroups,
2325  best_path->transitionSpace,
2326  subplan);
2327 
2328  copy_generic_path_info(&plan->plan, (Path *) best_path);
2329 
2330  return plan;
2331 }
2332 
2333 /*
2334  * Given a groupclause for a collection of grouping sets, produce the
2335  * corresponding groupColIdx.
2336  *
2337  * root->grouping_map maps the tleSortGroupRef to the actual column position in
2338  * the input tuple. So we get the ref from the entries in the groupclause and
2339  * look them up there.
2340  */
2341 static AttrNumber *
2342 remap_groupColIdx(PlannerInfo *root, List *groupClause)
2343 {
2344  AttrNumber *grouping_map = root->grouping_map;
2345  AttrNumber *new_grpColIdx;
2346  ListCell *lc;
2347  int i;
2348 
2349  Assert(grouping_map);
2350 
2351  new_grpColIdx = palloc0(sizeof(AttrNumber) * list_length(groupClause));
2352 
2353  i = 0;
2354  foreach(lc, groupClause)
2355  {
2356  SortGroupClause *clause = lfirst(lc);
2357 
2358  new_grpColIdx[i++] = grouping_map[clause->tleSortGroupRef];
2359  }
2360 
2361  return new_grpColIdx;
2362 }
2363 
2364 /*
2365  * create_groupingsets_plan
2366  * Create a plan for 'best_path' and (recursively) plans
2367  * for its subpaths.
2368  *
2369  * What we emit is an Agg plan with some vestigial Agg and Sort nodes
2370  * hanging off the side. The top Agg implements the last grouping set
2371  * specified in the GroupingSetsPath, and any additional grouping sets
2372  * each give rise to a subsidiary Agg and Sort node in the top Agg's
2373  * "chain" list. These nodes don't participate in the plan directly,
2374  * but they are a convenient way to represent the required data for
2375  * the extra steps.
2376  *
2377  * Returns a Plan node.
2378  */
2379 static Plan *
2380 create_groupingsets_plan(PlannerInfo *root, GroupingSetsPath *best_path)
2381 {
2382  Agg *plan;
2383  Plan *subplan;
2384  List *rollups = best_path->rollups;
2385  AttrNumber *grouping_map;
2386  int maxref;
2387  List *chain;
2388  ListCell *lc;
2389 
2390  /* Shouldn't get here without grouping sets */
2391  Assert(root->parse->groupingSets);
2392  Assert(rollups != NIL);
2393 
2394  /*
2395  * Agg can project, so no need to be terribly picky about child tlist, but
2396  * we do need grouping columns to be available
2397  */
2398  subplan = create_plan_recurse(root, best_path->subpath, CP_LABEL_TLIST);
2399 
2400  /*
2401  * Compute the mapping from tleSortGroupRef to column index in the child's
2402  * tlist. First, identify max SortGroupRef in groupClause, for array
2403  * sizing.
2404  */
2405  maxref = 0;
2406  foreach(lc, root->parse->groupClause)
2407  {
2408  SortGroupClause *gc = (SortGroupClause *) lfirst(lc);
2409 
2410  if (gc->tleSortGroupRef > maxref)
2411  maxref = gc->tleSortGroupRef;
2412  }
2413 
2414  grouping_map = (AttrNumber *) palloc0((maxref + 1) * sizeof(AttrNumber));
2415 
2416  /* Now look up the column numbers in the child's tlist */
2417  foreach(lc, root->parse->groupClause)
2418  {
2419  SortGroupClause *gc = (SortGroupClause *) lfirst(lc);
2420  TargetEntry *tle = get_sortgroupclause_tle(gc, subplan->targetlist);
2421 
2422  grouping_map[gc->tleSortGroupRef] = tle->resno;
2423  }
2424 
2425  /*
2426  * During setrefs.c, we'll need the grouping_map to fix up the cols lists
2427  * in GroupingFunc nodes. Save it for setrefs.c to use.
2428  */
2429  Assert(root->grouping_map == NULL);
2430  root->grouping_map = grouping_map;
2431 
2432  /*
2433  * Generate the side nodes that describe the other sort and group
2434  * operations besides the top one. Note that we don't worry about putting
2435  * accurate cost estimates in the side nodes; only the topmost Agg node's
2436  * costs will be shown by EXPLAIN.
2437  */
2438  chain = NIL;
2439  if (list_length(rollups) > 1)
2440  {
2441  bool is_first_sort = ((RollupData *) linitial(rollups))->is_hashed;
2442 
2443  for_each_from(lc, rollups, 1)
2444  {
2445  RollupData *rollup = lfirst(lc);
2446  AttrNumber *new_grpColIdx;
2447  Plan *sort_plan = NULL;
2448  Plan *agg_plan;
2449  AggStrategy strat;
2450 
2451  new_grpColIdx = remap_groupColIdx(root, rollup->groupClause);
2452 
2453  if (!rollup->is_hashed && !is_first_sort)
2454  {
2455  sort_plan = (Plan *)
2456  make_sort_from_groupcols(rollup->groupClause,
2457  new_grpColIdx,
2458  subplan);
2459  }
2460 
2461  if (!rollup->is_hashed)
2462  is_first_sort = false;
2463 
2464  if (rollup->is_hashed)
2465  strat = AGG_HASHED;
2466  else if (list_length(linitial(rollup->gsets)) == 0)
2467  strat = AGG_PLAIN;
2468  else
2469  strat = AGG_SORTED;
2470 
2471  agg_plan = (Plan *) make_agg(NIL,
2472  NIL,
2473  strat,
2474  AGGSPLIT_SIMPLE,
2475  list_length((List *) linitial(rollup->gsets)),
2476  new_grpColIdx,
2477  extract_grouping_ops(rollup->groupClause),
2478  extract_grouping_collations(rollup->groupClause, subplan->targetlist),
2479  rollup->gsets,
2480  NIL,
2481  rollup->numGroups,
2482  best_path->transitionSpace,
2483  sort_plan);
2484 
2485  /*
2486  * Remove stuff we don't need to avoid bloating debug output.
2487  */
2488  if (sort_plan)
2489  {
2490  sort_plan->targetlist = NIL;
2491  sort_plan->lefttree = NULL;
2492  }
2493 
2494  chain = lappend(chain, agg_plan);
2495  }
2496  }
2497 
2498  /*
2499  * Now make the real Agg node
2500  */
2501  {
2502  RollupData *rollup = linitial(rollups);
2503  AttrNumber *top_grpColIdx;
2504  int numGroupCols;
2505 
2506  top_grpColIdx = remap_groupColIdx(root, rollup->groupClause);
2507 
2508  numGroupCols = list_length((List *) linitial(rollup->gsets));
2509 
2510  plan = make_agg(build_path_tlist(root, &best_path->path),
2511  best_path->qual,
2512  best_path->aggstrategy,
2513  AGGSPLIT_SIMPLE,
2514  numGroupCols,
2515  top_grpColIdx,
2516  extract_grouping_ops(rollup->groupClause),
2517  extract_grouping_collations(rollup->groupClause, subplan->targetlist),
2518  rollup->gsets,
2519  chain,
2520  rollup->numGroups,
2521  best_path->transitionSpace,
2522  subplan);
2523 
2524  /* Copy cost data from Path to Plan */
2525  copy_generic_path_info(&plan->plan, &best_path->path);
2526  }
2527 
2528  return (Plan *) plan;
2529 }
2530 
2531 /*
2532  * create_minmaxagg_plan
2533  *
2534  * Create a Result plan for 'best_path' and (recursively) plans
2535  * for its subpaths.
2536  */
2537 static Result *
2538 create_minmaxagg_plan(PlannerInfo *root, MinMaxAggPath *best_path)
2539 {
2540  Result *plan;
2541  List *tlist;
2542  ListCell *lc;
2543 
2544  /* Prepare an InitPlan for each aggregate's subquery. */
2545  foreach(lc, best_path->mmaggregates)
2546  {
2547  MinMaxAggInfo *mminfo = (MinMaxAggInfo *) lfirst(lc);
2548  PlannerInfo *subroot = mminfo->subroot;
2549  Query *subparse = subroot->parse;
2550  Plan *plan;
2551 
2552  /*
2553  * Generate the plan for the subquery. We already have a Path, but we
2554  * have to convert it to a Plan and attach a LIMIT node above it.
2555  * Since we are entering a different planner context (subroot),
2556  * recurse to create_plan not create_plan_recurse.
2557  */
2558  plan = create_plan(subroot, mminfo->path);
2559 
2560  plan = (Plan *) make_limit(plan,
2561  subparse->limitOffset,
2562  subparse->limitCount,
2563  subparse->limitOption,
2564  0, NULL, NULL, NULL);
2565 
2566  /* Must apply correct cost/width data to Limit node */
2567  plan->startup_cost = mminfo->path->startup_cost;
2568  plan->total_cost = mminfo->pathcost;
2569  plan->plan_rows = 1;
2570  plan->plan_width = mminfo->path->pathtarget->width;
2571  plan->parallel_aware = false;
2572  plan->parallel_safe = mminfo->path->parallel_safe;
2573 
2574  /* Convert the plan into an InitPlan in the outer query. */
2575  SS_make_initplan_from_plan(root, subroot, plan, mminfo->param);
2576  }
2577 
2578  /* Generate the output plan --- basically just a Result */
2579  tlist = build_path_tlist(root, &best_path->path);
2580 
2581  plan = make_result(tlist, (Node *) best_path->quals, NULL);
2582 
2583  copy_generic_path_info(&plan->plan, (Path *) best_path);
2584 
2585  /*
2586  * During setrefs.c, we'll need to replace references to the Agg nodes
2587  * with InitPlan output params. (We can't just do that locally in the
2588  * MinMaxAgg node, because path nodes above here may have Agg references
2589  * as well.) Save the mmaggregates list to tell setrefs.c to do that.
2590  */
2591  Assert(root->minmax_aggs == NIL);
2592  root->minmax_aggs = best_path->mmaggregates;
2593 
2594  return plan;
2595 }
2596 
2597 /*
2598  * create_windowagg_plan
2599  *
2600  * Create a WindowAgg plan for 'best_path' and (recursively) plans
2601  * for its subpaths.
2602  */
2603 static WindowAgg *
2604 create_windowagg_plan(PlannerInfo *root, WindowAggPath *best_path)
2605 {
2606  WindowAgg *plan;
2607  WindowClause *wc = best_path->winclause;
2608  int numPart = list_length(wc->partitionClause);
2609  int numOrder = list_length(wc->orderClause);
2610  Plan *subplan;
2611  List *tlist;
2612  int partNumCols;
2613  AttrNumber *partColIdx;
2614  Oid *partOperators;
2615  Oid *partCollations;
2616  int ordNumCols;
2617  AttrNumber *ordColIdx;
2618  Oid *ordOperators;
2619  Oid *ordCollations;
2620  ListCell *lc;
2621 
2622  /*
2623  * Choice of tlist here is motivated by the fact that WindowAgg will be
2624  * storing the input rows of window frames in a tuplestore; it therefore
2625  * behooves us to request a small tlist to avoid wasting space. We do of
2626  * course need grouping columns to be available.
2627  */
2628  subplan = create_plan_recurse(root, best_path->subpath,
2629  CP_LABEL_TLIST | CP_SMALL_TLIST);
2630 
2631  tlist = build_path_tlist(root, &best_path->path);
2632 
2633  /*
2634  * Convert SortGroupClause lists into arrays of attr indexes and equality
2635  * operators, as wanted by executor. (Note: in principle, it's possible
2636  * to drop some of the sort columns, if they were proved redundant by
2637  * pathkey logic. However, it doesn't seem worth going out of our way to
2638  * optimize such cases. In any case, we must *not* remove the ordering
2639  * column for RANGE OFFSET cases, as the executor needs that for in_range
2640  * tests even if it's known to be equal to some partitioning column.)
2641  */
2642  partColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numPart);
2643  partOperators = (Oid *) palloc(sizeof(Oid) * numPart);
2644  partCollations = (Oid *) palloc(sizeof(Oid) * numPart);
2645 
2646  partNumCols = 0;
2647  foreach(lc, wc->partitionClause)
2648  {
2649  SortGroupClause *sgc = (SortGroupClause *) lfirst(lc);
2650  TargetEntry *tle = get_sortgroupclause_tle(sgc, subplan->targetlist);
2651 
2652  Assert(OidIsValid(sgc->eqop));
2653  partColIdx[partNumCols] = tle->resno;
2654  partOperators[partNumCols] = sgc->eqop;
2655  partCollations[partNumCols] = exprCollation((Node *) tle->expr);
2656  partNumCols++;
2657  }
2658 
2659  ordColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numOrder);
2660  ordOperators = (Oid *) palloc(sizeof(Oid) * numOrder);
2661  ordCollations = (Oid *) palloc(sizeof(Oid) * numOrder);
2662 
2663  ordNumCols = 0;
2664  foreach(lc, wc->orderClause)
2665  {
2666  SortGroupClause *sgc = (SortGroupClause *) lfirst(lc);
2667  TargetEntry *tle = get_sortgroupclause_tle(sgc, subplan->targetlist);
2668 
2669  Assert(OidIsValid(sgc->eqop));
2670  ordColIdx[ordNumCols] = tle->resno;
2671  ordOperators[ordNumCols] = sgc->eqop;
2672  ordCollations[ordNumCols] = exprCollation((Node *) tle->expr);
2673  ordNumCols++;
2674  }
2675 
2676  /* And finally we can make the WindowAgg node */
2677  plan = make_windowagg(tlist,
2678  wc->winref,
2679  partNumCols,
2680  partColIdx,
2681  partOperators,
2682  partCollations,
2683  ordNumCols,
2684  ordColIdx,
2685  ordOperators,
2686  ordCollations,
2687  wc->frameOptions,
2688  wc->startOffset,
2689  wc->endOffset,
2690  wc->startInRangeFunc,
2691  wc->endInRangeFunc,
2692  wc->inRangeColl,
2693  wc->inRangeAsc,
2694  wc->inRangeNullsFirst,
2695  wc->runCondition,
2696  best_path->qual,
2697  best_path->topwindow,
2698  subplan);
2699 
2700  copy_generic_path_info(&plan->plan, (Path *) best_path);
2701 
2702  return plan;
2703 }
2704 
2705 /*
2706  * create_setop_plan
2707  *
2708  * Create a SetOp plan for 'best_path' and (recursively) plans
2709  * for its subpaths.
2710  */
2711 static SetOp *
2712 create_setop_plan(PlannerInfo *root, SetOpPath *best_path, int flags)
2713 {
2714  SetOp *plan;
2715  Plan *subplan;
2716  long numGroups;
2717 
2718  /*
2719  * SetOp doesn't project, so tlist requirements pass through; moreover we
2720  * need grouping columns to be labeled.
2721  */
2722  subplan = create_plan_recurse(root, best_path->subpath,
2723  flags | CP_LABEL_TLIST);
2724 
2725  /* Convert numGroups to long int --- but 'ware overflow! */
2726  numGroups = clamp_cardinality_to_long(best_path->numGroups);
2727 
2728  plan = make_setop(best_path->cmd,
2729  best_path->strategy,
2730  subplan,
2731  best_path->distinctList,
2732  best_path->flagColIdx,
2733  best_path->firstFlag,
2734  numGroups);
2735 
2736  copy_generic_path_info(&plan->plan, (Path *) best_path);
2737 
2738  return plan;
2739 }
2740 
2741 /*
2742  * create_recursiveunion_plan
2743  *
2744  * Create a RecursiveUnion plan for 'best_path' and (recursively) plans
2745  * for its subpaths.
2746  */
2747 static RecursiveUnion *
2748 create_recursiveunion_plan(PlannerInfo *root, RecursiveUnionPath *best_path)
2749 {
2750  RecursiveUnion *plan;
2751  Plan *leftplan;
2752  Plan *rightplan;
2753  List *tlist;
2754  long numGroups;
2755 
2756  /* Need both children to produce same tlist, so force it */
2757  leftplan = create_plan_recurse(root, best_path->leftpath, CP_EXACT_TLIST);
2758  rightplan = create_plan_recurse(root, best_path->rightpath, CP_EXACT_TLIST);
2759 
2760  tlist = build_path_tlist(root, &best_path->path);
2761 
2762  /* Convert numGroups to long int --- but 'ware overflow! */
2763  numGroups = clamp_cardinality_to_long(best_path->numGroups);
2764 
2765  plan = make_recursive_union(tlist,
2766  leftplan,
2767  rightplan,
2768  best_path->wtParam,
2769  best_path->distinctList,
2770  numGroups);
2771 
2772  copy_generic_path_info(&plan->plan, (Path *) best_path);
2773 
2774  return plan;
2775 }
2776 
2777 /*
2778  * create_lockrows_plan
2779  *
2780  * Create a LockRows plan for 'best_path' and (recursively) plans
2781  * for its subpaths.
2782  */
2783 static LockRows *
2784 create_lockrows_plan(PlannerInfo *root, LockRowsPath *best_path,
2785  int flags)
2786 {
2787  LockRows *plan;
2788  Plan *subplan;
2789 
2790  /* LockRows doesn't project, so tlist requirements pass through */
2791  subplan = create_plan_recurse(root, best_path->subpath, flags);
2792 
2793  plan = make_lockrows(subplan, best_path->rowMarks, best_path->epqParam);
2794 
2795  copy_generic_path_info(&plan->plan, (Path *) best_path);
2796 
2797  return plan;
2798 }
2799 
2800 /*
2801  * create_modifytable_plan
2802  * Create a ModifyTable plan for 'best_path'.
2803  *
2804  * Returns a Plan node.
2805  */
2806 static ModifyTable *
2807 create_modifytable_plan(PlannerInfo *root, ModifyTablePath *best_path)
2808 {
2809  ModifyTable *plan;
2810  Path *subpath = best_path->subpath;
2811  Plan *subplan;
2812 
2813  /* Subplan must produce exactly the specified tlist */
2814  subplan = create_plan_recurse(root, subpath, CP_EXACT_TLIST);
2815 
2816  /* Transfer resname/resjunk labeling, too, to keep executor happy */
2817  apply_tlist_labeling(subplan->targetlist, root->processed_tlist);
2818 
2819  plan = make_modifytable(root,
2820  subplan,
2821  best_path->operation,
2822  best_path->canSetTag,
2823  best_path->nominalRelation,
2824  best_path->rootRelation,
2825  best_path->partColsUpdated,
2826  best_path->resultRelations,
2827  best_path->updateColnosLists,
2828  best_path->withCheckOptionLists,
2829  best_path->returningLists,
2830  best_path->rowMarks,
2831  best_path->onconflict,
2832  best_path->mergeActionLists,
2833  best_path->epqParam);
2834 
2835  copy_generic_path_info(&plan->plan, &best_path->path);
2836 
2837  return plan;
2838 }
2839 
2840 /*
2841  * create_limit_plan
2842  *
2843  * Create a Limit plan for 'best_path' and (recursively) plans
2844  * for its subpaths.
2845  */
2846 static Limit *
2847 create_limit_plan(PlannerInfo *root, LimitPath *best_path, int flags)
2848 {
2849  Limit *plan;
2850  Plan *subplan;
2851  int numUniqkeys = 0;
2852  AttrNumber *uniqColIdx = NULL;
2853  Oid *uniqOperators = NULL;
2854  Oid *uniqCollations = NULL;
2855 
2856  /* Limit doesn't project, so tlist requirements pass through */
2857  subplan = create_plan_recurse(root, best_path->subpath, flags);
2858 
2859  /* Extract information necessary for comparing rows for WITH TIES. */
2860  if (best_path->limitOption == LIMIT_OPTION_WITH_TIES)
2861  {
2862  Query *parse = root->parse;
2863  ListCell *l;
2864 
2865  numUniqkeys = list_length(parse->sortClause);
2866  uniqColIdx = (AttrNumber *) palloc(numUniqkeys * sizeof(AttrNumber));
2867  uniqOperators = (Oid *) palloc(numUniqkeys * sizeof(Oid));
2868  uniqCollations = (Oid *) palloc(numUniqkeys * sizeof(Oid));
2869 
2870  numUniqkeys = 0;
2871  foreach(l, parse->sortClause)
2872  {
2873  SortGroupClause *sortcl = (SortGroupClause *) lfirst(l);
2874  TargetEntry *tle = get_sortgroupclause_tle(sortcl, parse->targetList);
2875 
2876  uniqColIdx[numUniqkeys] = tle->resno;
2877  uniqOperators[numUniqkeys] = sortcl->eqop;
2878  uniqCollations[numUniqkeys] = exprCollation((Node *) tle->expr);
2879  numUniqkeys++;
2880  }
2881  }
2882 
2883  plan = make_limit(subplan,
2884  best_path->limitOffset,
2885  best_path->limitCount,
2886  best_path->limitOption,
2887  numUniqkeys, uniqColIdx, uniqOperators, uniqCollations);
2888 
2889  copy_generic_path_info(&plan->plan, (Path *) best_path);
2890 
2891  return plan;
2892 }
2893 
2894 
2895 /*****************************************************************************
2896  *
2897  * BASE-RELATION SCAN METHODS
2898  *
2899  *****************************************************************************/
2900 
2901 
2902 /*
2903  * create_seqscan_plan
2904  * Returns a seqscan plan for the base relation scanned by 'best_path'
2905  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
2906  */
2907 static SeqScan *
2908 create_seqscan_plan(PlannerInfo *root, Path *best_path,
2909  List *tlist, List *scan_clauses)
2910 {
2911  SeqScan *scan_plan;
2912  Index scan_relid = best_path->parent->relid;
2913 
2914  /* it should be a base rel... */
2915  Assert(scan_relid > 0);
2916  Assert(best_path->parent->rtekind == RTE_RELATION);
2917 
2918  /* Sort clauses into best execution order */
2919  scan_clauses = order_qual_clauses(root, scan_clauses);
2920 
2921  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
2922  scan_clauses = extract_actual_clauses(scan_clauses, false);
2923 
2924  /* Replace any outer-relation variables with nestloop params */
2925  if (best_path->param_info)
2926  {
2927  scan_clauses = (List *)
2928  replace_nestloop_params(root, (Node *) scan_clauses);
2929  }
2930 
2931  scan_plan = make_seqscan(tlist,
2932  scan_clauses,
2933  scan_relid);
2934 
2935  copy_generic_path_info(&scan_plan->scan.plan, best_path);
2936 
2937  return scan_plan;
2938 }
2939 
2940 /*
2941  * create_samplescan_plan
2942  * Returns a samplescan plan for the base relation scanned by 'best_path'
2943  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
2944  */
2945 static SampleScan *
2946 create_samplescan_plan(PlannerInfo *root, Path *best_path,
2947  List *tlist, List *scan_clauses)
2948 {
2949  SampleScan *scan_plan;
2950  Index scan_relid = best_path->parent->relid;
2951  RangeTblEntry *rte;
2952  TableSampleClause *tsc;
2953 
2954  /* it should be a base rel with a tablesample clause... */
2955  Assert(scan_relid > 0);
2956  rte = planner_rt_fetch(scan_relid, root);
2957  Assert(rte->rtekind == RTE_RELATION);
2958  tsc = rte->tablesample;
2959  Assert(tsc != NULL);
2960 
2961  /* Sort clauses into best execution order */
2962  scan_clauses = order_qual_clauses(root, scan_clauses);
2963 
2964  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
2965  scan_clauses = extract_actual_clauses(scan_clauses, false);
2966 
2967  /* Replace any outer-relation variables with nestloop params */
2968  if (best_path->param_info)
2969  {
2970  scan_clauses = (List *)
2971  replace_nestloop_params(root, (Node *) scan_clauses);
2972  tsc = (TableSampleClause *)
2973  replace_nestloop_params(root, (Node *) tsc);
2974  }
2975 
2976  scan_plan = make_samplescan(tlist,
2977  scan_clauses,
2978  scan_relid,
2979  tsc);
2980 
2981  copy_generic_path_info(&scan_plan->scan.plan, best_path);
2982 
2983  return scan_plan;
2984 }
2985 
2986 /*
2987  * create_indexscan_plan
2988  * Returns an indexscan plan for the base relation scanned by 'best_path'
2989  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
2990  *
2991  * We use this for both plain IndexScans and IndexOnlyScans, because the
2992  * qual preprocessing work is the same for both. Note that the caller tells
2993  * us which to build --- we don't look at best_path->path.pathtype, because
2994  * create_bitmap_subplan needs to be able to override the prior decision.
2995  */
2996 static Scan *
2997 create_indexscan_plan(PlannerInfo *root,
2998  IndexPath *best_path,
2999  List *tlist,
3000  List *scan_clauses,
3001  bool indexonly)
3002 {
3003  Scan *scan_plan;
3004  List *indexclauses = best_path->indexclauses;
3005  List *indexorderbys = best_path->indexorderbys;
3006  Index baserelid = best_path->path.parent->relid;
3007  IndexOptInfo *indexinfo = best_path->indexinfo;
3008  Oid indexoid = indexinfo->indexoid;
3009  List *qpqual;
3010  List *stripped_indexquals;
3011  List *fixed_indexquals;
3012  List *fixed_indexorderbys;
3013  List *indexorderbyops = NIL;
3014  ListCell *l;
3015 
3016  /* it should be a base rel... */
3017  Assert(baserelid > 0);
3018  Assert(best_path->path.parent->rtekind == RTE_RELATION);
3019 
3020  /*
3021  * Extract the index qual expressions (stripped of RestrictInfos) from the
3022  * IndexClauses list, and prepare a copy with index Vars substituted for
3023  * table Vars. (This step also does replace_nestloop_params on the
3024  * fixed_indexquals.)
3025  */
3026  fix_indexqual_references(root, best_path,
3027  &stripped_indexquals,
3028  &fixed_indexquals);
3029 
3030  /*
3031  * Likewise fix up index attr references in the ORDER BY expressions.
3032  */
3033  fixed_indexorderbys = fix_indexorderby_references(root, best_path);
3034 
3035  /*
3036  * The qpqual list must contain all restrictions not automatically handled
3037  * by the index, other than pseudoconstant clauses which will be handled
3038  * by a separate gating plan node. All the predicates in the indexquals
3039  * will be checked (either by the index itself, or by nodeIndexscan.c),
3040  * but if there are any "special" operators involved then they must be
3041  * included in qpqual. The upshot is that qpqual must contain
3042  * scan_clauses minus whatever appears in indexquals.
3043  *
3044  * is_redundant_with_indexclauses() detects cases where a scan clause is
3045  * present in the indexclauses list or is generated from the same
3046  * EquivalenceClass as some indexclause, and is therefore redundant with
3047  * it, though not equal. (The latter happens when indxpath.c prefers a
3048  * different derived equality than what generate_join_implied_equalities
3049  * picked for a parameterized scan's ppi_clauses.) Note that it will not
3050  * match to lossy index clauses, which is critical because we have to
3051  * include the original clause in qpqual in that case.
3052  *
3053  * In some situations (particularly with OR'd index conditions) we may
3054  * have scan_clauses that are not equal to, but are logically implied by,
3055  * the index quals; so we also try a predicate_implied_by() check to see
3056  * if we can discard quals that way. (predicate_implied_by assumes its
3057  * first input contains only immutable functions, so we have to check
3058  * that.)
3059  *
3060  * Note: if you change this bit of code you should also look at
3061  * extract_nonindex_conditions() in costsize.c.
3062  */
3063  qpqual = NIL;
3064  foreach(l, scan_clauses)
3065  {
3066  RestrictInfo *rinfo = lfirst_node(RestrictInfo, l);
3067 
3068  if (rinfo->pseudoconstant)
3069  continue; /* we may drop pseudoconstants here */
3070  if (is_redundant_with_indexclauses(rinfo, indexclauses))
3071  continue; /* dup or derived from same EquivalenceClass */
3072  if (!contain_mutable_functions((Node *) rinfo->clause) &&
3073  predicate_implied_by(list_make1(rinfo->clause), stripped_indexquals,
3074  false))
3075  continue; /* provably implied by indexquals */
3076  qpqual = lappend(qpqual, rinfo);
3077  }
3078 
3079  /* Sort clauses into best execution order */
3080  qpqual = order_qual_clauses(root, qpqual);
3081 
3082  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3083  qpqual = extract_actual_clauses(qpqual, false);
3084 
3085  /*
3086  * We have to replace any outer-relation variables with nestloop params in
3087  * the indexqualorig, qpqual, and indexorderbyorig expressions. A bit
3088  * annoying to have to do this separately from the processing in
3089  * fix_indexqual_references --- rethink this when generalizing the inner
3090  * indexscan support. But note we can't really do this earlier because
3091  * it'd break the comparisons to predicates above ... (or would it? Those
3092  * wouldn't have outer refs)
3093  */
3094  if (best_path->path.param_info)
3095  {
3096  stripped_indexquals = (List *)
3097  replace_nestloop_params(root, (Node *) stripped_indexquals);
3098  qpqual = (List *)
3099  replace_nestloop_params(root, (Node *) qpqual);
3100  indexorderbys = (List *)
3101  replace_nestloop_params(root, (Node *) indexorderbys);
3102  }
3103 
3104  /*
3105  * If there are ORDER BY expressions, look up the sort operators for their
3106  * result datatypes.
3107  */
3108  if (indexorderbys)
3109  {
3110  ListCell *pathkeyCell,
3111  *exprCell;
3112 
3113  /*
3114  * PathKey contains OID of the btree opfamily we're sorting by, but
3115  * that's not quite enough because we need the expression's datatype
3116  * to look up the sort operator in the operator family.
3117  */
3118  Assert(list_length(best_path->path.pathkeys) == list_length(indexorderbys));
3119  forboth(pathkeyCell, best_path->path.pathkeys, exprCell, indexorderbys)
3120  {
3121  PathKey *pathkey = (PathKey *) lfirst(pathkeyCell);
3122  Node *expr = (Node *) lfirst(exprCell);
3123  Oid exprtype = exprType(expr);
3124  Oid sortop;
3125 
3126  /* Get sort operator from opfamily */
3127  sortop = get_opfamily_member(pathkey->pk_opfamily,
3128  exprtype,
3129  exprtype,
3130  pathkey->pk_strategy);
3131  if (!OidIsValid(sortop))
3132  elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3133  pathkey->pk_strategy, exprtype, exprtype, pathkey->pk_opfamily);
3134  indexorderbyops = lappend_oid(indexorderbyops, sortop);
3135  }
3136  }
3137 
3138  /*
3139  * For an index-only scan, we must mark indextlist entries as resjunk if
3140  * they are columns that the index AM can't return; this cues setrefs.c to
3141  * not generate references to those columns.
3142  */
3143  if (indexonly)
3144  {
3145  int i = 0;
3146 
3147  foreach(l, indexinfo->indextlist)
3148  {
3149  TargetEntry *indextle = (TargetEntry *) lfirst(l);
3150 
3151  indextle->resjunk = !indexinfo->canreturn[i];
3152  i++;
3153  }
3154  }
3155 
3156  /* Finally ready to build the plan node */
3157  if (indexonly)
3158  scan_plan = (Scan *) make_indexonlyscan(tlist,
3159  qpqual,
3160  baserelid,
3161  indexoid,
3162  fixed_indexquals,
3163  stripped_indexquals,
3164  fixed_indexorderbys,
3165  indexinfo->indextlist,
3166  best_path->indexscandir);
3167  else
3168  scan_plan = (Scan *) make_indexscan(tlist,
3169  qpqual,
3170  baserelid,
3171  indexoid,
3172  fixed_indexquals,
3173  stripped_indexquals,
3174  fixed_indexorderbys,
3175  indexorderbys,
3176  indexorderbyops,
3177  best_path->indexscandir);
3178 
3179  copy_generic_path_info(&scan_plan->plan, &best_path->path);
3180 
3181  return scan_plan;
3182 }
3183 
3184 /*
3185  * create_bitmap_scan_plan
3186  * Returns a bitmap scan plan for the base relation scanned by 'best_path'
3187  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3188  */
3189 static BitmapHeapScan *
3190 create_bitmap_scan_plan(PlannerInfo *root,
3191  BitmapHeapPath *best_path,
3192  List *tlist,
3193  List *scan_clauses)
3194 {
3195  Index baserelid = best_path->path.parent->relid;
3196  Plan *bitmapqualplan;
3197  List *bitmapqualorig;
3198  List *indexquals;
3199  List *indexECs;
3200  List *qpqual;
3201  ListCell *l;
3202  BitmapHeapScan *scan_plan;
3203 
3204  /* it should be a base rel... */
3205  Assert(baserelid > 0);
3206  Assert(best_path->path.parent->rtekind == RTE_RELATION);
3207 
3208  /* Process the bitmapqual tree into a Plan tree and qual lists */
3209  bitmapqualplan = create_bitmap_subplan(root, best_path->bitmapqual,
3210  &bitmapqualorig, &indexquals,
3211  &indexECs);
3212 
3213  if (best_path->path.parallel_aware)
3214  bitmap_subplan_mark_shared(bitmapqualplan);
3215 
3216  /*
3217  * The qpqual list must contain all restrictions not automatically handled
3218  * by the index, other than pseudoconstant clauses which will be handled
3219  * by a separate gating plan node. All the predicates in the indexquals
3220  * will be checked (either by the index itself, or by
3221  * nodeBitmapHeapscan.c), but if there are any "special" operators
3222  * involved then they must be added to qpqual. The upshot is that qpqual
3223  * must contain scan_clauses minus whatever appears in indexquals.
3224  *
3225  * This loop is similar to the comparable code in create_indexscan_plan(),
3226  * but with some differences because it has to compare the scan clauses to
3227  * stripped (no RestrictInfos) indexquals. See comments there for more
3228  * info.
3229  *
3230  * In normal cases simple equal() checks will be enough to spot duplicate
3231  * clauses, so we try that first. We next see if the scan clause is
3232  * redundant with any top-level indexqual by virtue of being generated
3233  * from the same EC. After that, try predicate_implied_by().
3234  *
3235  * Unlike create_indexscan_plan(), the predicate_implied_by() test here is
3236  * useful for getting rid of qpquals that are implied by index predicates,
3237  * because the predicate conditions are included in the "indexquals"
3238  * returned by create_bitmap_subplan(). Bitmap scans have to do it that
3239  * way because predicate conditions need to be rechecked if the scan
3240  * becomes lossy, so they have to be included in bitmapqualorig.
3241  */
3242  qpqual = NIL;
3243  foreach(l, scan_clauses)
3244  {
3245  RestrictInfo *rinfo = lfirst_node(RestrictInfo, l);
3246  Node *clause = (Node *) rinfo->clause;
3247 
3248  if (rinfo->pseudoconstant)
3249  continue; /* we may drop pseudoconstants here */
3250  if (list_member(indexquals, clause))
3251  continue; /* simple duplicate */
3252  if (rinfo->parent_ec && list_member_ptr(indexECs, rinfo->parent_ec))
3253  continue; /* derived from same EquivalenceClass */
3254  if (!contain_mutable_functions(clause) &&
3255  predicate_implied_by(list_make1(clause), indexquals, false))
3256  continue; /* provably implied by indexquals */
3257  qpqual = lappend(qpqual, rinfo);
3258  }
3259 
3260  /* Sort clauses into best execution order */
3261  qpqual = order_qual_clauses(root, qpqual);
3262 
3263  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3264  qpqual = extract_actual_clauses(qpqual, false);
3265 
3266  /*
3267  * When dealing with special operators, we will at this point have
3268  * duplicate clauses in qpqual and bitmapqualorig. We may as well drop
3269  * 'em from bitmapqualorig, since there's no point in making the tests
3270  * twice.
3271  */
3272  bitmapqualorig = list_difference_ptr(bitmapqualorig, qpqual);
3273 
3274  /*
3275  * We have to replace any outer-relation variables with nestloop params in
3276  * the qpqual and bitmapqualorig expressions. (This was already done for
3277  * expressions attached to plan nodes in the bitmapqualplan tree.)
3278  */
3279  if (best_path->path.param_info)
3280  {
3281  qpqual = (List *)
3282  replace_nestloop_params(root, (Node *) qpqual);
3283  bitmapqualorig = (List *)
3284  replace_nestloop_params(root, (Node *) bitmapqualorig);
3285  }
3286 
3287  /* Finally ready to build the plan node */
3288  scan_plan = make_bitmap_heapscan(tlist,
3289  qpqual,
3290  bitmapqualplan,
3291  bitmapqualorig,
3292  baserelid);
3293 
3294  copy_generic_path_info(&scan_plan->scan.plan, &best_path->path);
3295 
3296  return scan_plan;
3297 }
3298 
3299 /*
3300  * Given a bitmapqual tree, generate the Plan tree that implements it
3301  *
3302  * As byproducts, we also return in *qual and *indexqual the qual lists
3303  * (in implicit-AND form, without RestrictInfos) describing the original index
3304  * conditions and the generated indexqual conditions. (These are the same in
3305  * simple cases, but when special index operators are involved, the former
3306  * list includes the special conditions while the latter includes the actual
3307  * indexable conditions derived from them.) Both lists include partial-index
3308  * predicates, because we have to recheck predicates as well as index
3309  * conditions if the bitmap scan becomes lossy.
3310  *
3311  * In addition, we return a list of EquivalenceClass pointers for all the
3312  * top-level indexquals that were possibly-redundantly derived from ECs.
3313  * This allows removal of scan_clauses that are redundant with such quals.
3314  * (We do not attempt to detect such redundancies for quals that are within
3315  * OR subtrees. This could be done in a less hacky way if we returned the
3316  * indexquals in RestrictInfo form, but that would be slower and still pretty
3317  * messy, since we'd have to build new RestrictInfos in many cases.)
3318  */
3319 static Plan *
3320 create_bitmap_subplan(PlannerInfo *root, Path *bitmapqual,
3321  List **qual, List **indexqual, List **indexECs)
3322 {
3323  Plan *plan;
3324 
3325  if (IsA(bitmapqual, BitmapAndPath))
3326  {
3327  BitmapAndPath *apath = (BitmapAndPath *) bitmapqual;
3328  List *subplans = NIL;
3329  List *subquals = NIL;
3330  List *subindexquals = NIL;
3331  List *subindexECs = NIL;
3332  ListCell *l;
3333 
3334  /*
3335  * There may well be redundant quals among the subplans, since a
3336  * top-level WHERE qual might have gotten used to form several
3337  * different index quals. We don't try exceedingly hard to eliminate
3338  * redundancies, but we do eliminate obvious duplicates by using
3339  * list_concat_unique.
3340  */
3341  foreach(l, apath->bitmapquals)
3342  {
3343  Plan *subplan;
3344  List *subqual;
3345  List *subindexqual;
3346  List *subindexEC;
3347 
3348  subplan = create_bitmap_subplan(root, (Path *) lfirst(l),
3349  &subqual, &subindexqual,
3350  &subindexEC);
3351  subplans = lappend(subplans, subplan);
3352  subquals = list_concat_unique(subquals, subqual);
3353  subindexquals = list_concat_unique(subindexquals, subindexqual);
3354  /* Duplicates in indexECs aren't worth getting rid of */
3355  subindexECs = list_concat(subindexECs, subindexEC);
3356  }
3357  plan = (Plan *) make_bitmap_and(subplans);
3358  plan->startup_cost = apath->path.startup_cost;
3359  plan->total_cost = apath->path.total_cost;
3360  plan->plan_rows =
3361  clamp_row_est(apath->bitmapselectivity * apath->path.parent->tuples);
3362  plan->plan_width = 0; /* meaningless */
3363  plan->parallel_aware = false;
3364  plan->parallel_safe = apath->path.parallel_safe;
3365  *qual = subquals;
3366  *indexqual = subindexquals;
3367  *indexECs = subindexECs;
3368  }
3369  else if (IsA(bitmapqual, BitmapOrPath))
3370  {
3371  BitmapOrPath *opath = (BitmapOrPath *) bitmapqual;
3372  List *subplans = NIL;
3373  List *subquals = NIL;
3374  List *subindexquals = NIL;
3375  bool const_true_subqual = false;
3376  bool const_true_subindexqual = false;
3377  ListCell *l;
3378 
3379  /*
3380  * Here, we only detect qual-free subplans. A qual-free subplan would
3381  * cause us to generate "... OR true ..." which we may as well reduce
3382  * to just "true". We do not try to eliminate redundant subclauses
3383  * because (a) it's not as likely as in the AND case, and (b) we might
3384  * well be working with hundreds or even thousands of OR conditions,
3385  * perhaps from a long IN list. The performance of list_append_unique
3386  * would be unacceptable.
3387  */
3388  foreach(l, opath->bitmapquals)
3389  {
3390  Plan *subplan;
3391  List *subqual;
3392  List *subindexqual;
3393  List *subindexEC;
3394 
3395  subplan = create_bitmap_subplan(root, (Path *) lfirst(l),
3396  &subqual, &subindexqual,
3397  &subindexEC);
3398  subplans = lappend(subplans, subplan);
3399  if (subqual == NIL)
3400  const_true_subqual = true;
3401  else if (!const_true_subqual)
3402  subquals = lappend(subquals,
3403  make_ands_explicit(subqual));
3404  if (subindexqual == NIL)
3405  const_true_subindexqual = true;
3406  else if (!const_true_subindexqual)
3407  subindexquals = lappend(subindexquals,
3408  make_ands_explicit(subindexqual));
3409  }
3410 
3411  /*
3412  * In the presence of ScalarArrayOpExpr quals, we might have built
3413  * BitmapOrPaths with just one subpath; don't add an OR step.
3414  */
3415  if (list_length(subplans) == 1)
3416  {
3417  plan = (Plan *) linitial(subplans);
3418  }
3419  else
3420  {
3421  plan = (Plan *) make_bitmap_or(subplans);
3422  plan->startup_cost = opath->path.startup_cost;
3423  plan->total_cost = opath->path.total_cost;
3424  plan->plan_rows =
3425  clamp_row_est(opath->bitmapselectivity * opath->path.parent->tuples);
3426  plan->plan_width = 0; /* meaningless */
3427  plan->parallel_aware = false;
3428  plan->parallel_safe = opath->path.parallel_safe;
3429  }
3430 
3431  /*
3432  * If there were constant-TRUE subquals, the OR reduces to constant
3433  * TRUE. Also, avoid generating one-element ORs, which could happen
3434  * due to redundancy elimination or ScalarArrayOpExpr quals.
3435  */
3436  if (const_true_subqual)
3437  *qual = NIL;
3438  else if (list_length(subquals) <= 1)
3439  *qual = subquals;
3440  else
3441  *qual = list_make1(make_orclause(subquals));
3442  if (const_true_subindexqual)
3443  *indexqual = NIL;
3444  else if (list_length(subindexquals) <= 1)
3445  *indexqual = subindexquals;
3446  else
3447  *indexqual = list_make1(make_orclause(subindexquals));
3448  *indexECs = NIL;
3449  }
3450  else if (IsA(bitmapqual, IndexPath))
3451  {
3452  IndexPath *ipath = (IndexPath *) bitmapqual;
3453  IndexScan *iscan;
3454  List *subquals;
3455  List *subindexquals;
3456  List *subindexECs;
3457  ListCell *l;
3458 
3459  /* Use the regular indexscan plan build machinery... */
3460  iscan = castNode(IndexScan,
3461  create_indexscan_plan(root, ipath,
3462  NIL, NIL, false));
3463  /* then convert to a bitmap indexscan */
3464  plan = (Plan *) make_bitmap_indexscan(iscan->scan.scanrelid,
3465  iscan->indexid,
3466  iscan->indexqual,
3467  iscan->indexqualorig);
3468  /* and set its cost/width fields appropriately */
3469  plan->startup_cost = 0.0;
3470  plan->total_cost = ipath->indextotalcost;
3471  plan->plan_rows =
3472  clamp_row_est(ipath->indexselectivity * ipath->path.parent->tuples);
3473  plan->plan_width = 0; /* meaningless */
3474  plan->parallel_aware = false;
3475  plan->parallel_safe = ipath->path.parallel_safe;
3476  /* Extract original index clauses, actual index quals, relevant ECs */
3477  subquals = NIL;
3478  subindexquals = NIL;
3479  subindexECs = NIL;
3480  foreach(l, ipath->indexclauses)
3481  {
3482  IndexClause *iclause = (IndexClause *) lfirst(l);
3483  RestrictInfo *rinfo = iclause->rinfo;
3484 
3485  Assert(!rinfo->pseudoconstant);
3486  subquals = lappend(subquals, rinfo->clause);
3487  subindexquals = list_concat(subindexquals,
3488  get_actual_clauses(iclause->indexquals));
3489  if (rinfo->parent_ec)
3490  subindexECs = lappend(subindexECs, rinfo->parent_ec);
3491  }
3492  /* We can add any index predicate conditions, too */
3493  foreach(l, ipath->indexinfo->indpred)
3494  {
3495  Expr *pred = (Expr *) lfirst(l);
3496 
3497  /*
3498  * We know that the index predicate must have been implied by the
3499  * query condition as a whole, but it may or may not be implied by
3500  * the conditions that got pushed into the bitmapqual. Avoid
3501  * generating redundant conditions.
3502  */
3503  if (!predicate_implied_by(list_make1(pred), subquals, false))
3504  {
3505  subquals = lappend(subquals, pred);
3506  subindexquals = lappend(subindexquals, pred);
3507  }
3508  }
3509  *qual = subquals;
3510  *indexqual = subindexquals;
3511  *indexECs = subindexECs;
3512  }
3513  else
3514  {
3515  elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
3516  plan = NULL; /* keep compiler quiet */
3517  }
3518 
3519  return plan;
3520 }
3521 
3522 /*
3523  * create_tidscan_plan
3524  * Returns a tidscan plan for the base relation scanned by 'best_path'
3525  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3526  */
3527 static TidScan *
3528 create_tidscan_plan(PlannerInfo *root, TidPath *best_path,
3529  List *tlist, List *scan_clauses)
3530 {
3531  TidScan *scan_plan;
3532  Index scan_relid = best_path->path.parent->relid;
3533  List *tidquals = best_path->tidquals;
3534 
3535  /* it should be a base rel... */
3536  Assert(scan_relid > 0);
3537  Assert(best_path->path.parent->rtekind == RTE_RELATION);
3538 
3539  /*
3540  * The qpqual list must contain all restrictions not enforced by the
3541  * tidquals list. Since tidquals has OR semantics, we have to be careful
3542  * about matching it up to scan_clauses. It's convenient to handle the
3543  * single-tidqual case separately from the multiple-tidqual case. In the
3544  * single-tidqual case, we look through the scan_clauses while they are
3545  * still in RestrictInfo form, and drop any that are redundant with the
3546  * tidqual.
3547  *
3548  * In normal cases simple pointer equality checks will be enough to spot
3549  * duplicate RestrictInfos, so we try that first.
3550  *
3551  * Another common case is that a scan_clauses entry is generated from the
3552  * same EquivalenceClass as some tidqual, and is therefore redundant with
3553  * it, though not equal.
3554  *
3555  * Unlike indexpaths, we don't bother with predicate_implied_by(); the
3556  * number of cases where it could win are pretty small.
3557  */
3558  if (list_length(tidquals) == 1)
3559  {
3560  List *qpqual = NIL;
3561  ListCell *l;
3562 
3563  foreach(l, scan_clauses)
3564  {
3565  RestrictInfo *rinfo = lfirst_node(RestrictInfo, l);
3566 
3567  if (rinfo->pseudoconstant)
3568  continue; /* we may drop pseudoconstants here */
3569  if (list_member_ptr(tidquals, rinfo))
3570  continue; /* simple duplicate */
3571  if (is_redundant_derived_clause(rinfo, tidquals))
3572  continue; /* derived from same EquivalenceClass */
3573  qpqual = lappend(qpqual, rinfo);
3574  }
3575  scan_clauses = qpqual;
3576  }
3577 
3578  /* Sort clauses into best execution order */
3579  scan_clauses = order_qual_clauses(root, scan_clauses);
3580 
3581  /* Reduce RestrictInfo lists to bare expressions; ignore pseudoconstants */
3582  tidquals = extract_actual_clauses(tidquals, false);
3583  scan_clauses = extract_actual_clauses(scan_clauses, false);
3584 
3585  /*
3586  * If we have multiple tidquals, it's more convenient to remove duplicate
3587  * scan_clauses after stripping the RestrictInfos. In this situation,
3588  * because the tidquals represent OR sub-clauses, they could not have come
3589  * from EquivalenceClasses so we don't have to worry about matching up
3590  * non-identical clauses. On the other hand, because tidpath.c will have
3591  * extracted those sub-clauses from some OR clause and built its own list,
3592  * we will certainly not have pointer equality to any scan clause. So
3593  * convert the tidquals list to an explicit OR clause and see if we can
3594  * match it via equal() to any scan clause.
3595  */
3596  if (list_length(tidquals) > 1)
3597  scan_clauses = list_difference(scan_clauses,
3598  list_make1(make_orclause(tidquals)));
3599 
3600  /* Replace any outer-relation variables with nestloop params */
3601  if (best_path->path.param_info)
3602  {
3603  tidquals = (List *)
3604  replace_nestloop_params(root, (Node *) tidquals);
3605  scan_clauses = (List *)
3606  replace_nestloop_params(root, (Node *) scan_clauses);
3607  }
3608 
3609  scan_plan = make_tidscan(tlist,
3610  scan_clauses,
3611  scan_relid,
3612  tidquals);
3613 
3614  copy_generic_path_info(&scan_plan->scan.plan, &best_path->path);
3615 
3616  return scan_plan;
3617 }
3618 
3619 /*
3620  * create_tidrangescan_plan
3621  * Returns a tidrangescan plan for the base relation scanned by 'best_path'
3622  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3623  */
3624 static TidRangeScan *
3625 create_tidrangescan_plan(PlannerInfo *root, TidRangePath *best_path,
3626  List *tlist, List *scan_clauses)
3627 {
3628  TidRangeScan *scan_plan;
3629  Index scan_relid = best_path->path.parent->relid;
3630  List *tidrangequals = best_path->tidrangequals;
3631 
3632  /* it should be a base rel... */
3633  Assert(scan_relid > 0);
3634  Assert(best_path->path.parent->rtekind == RTE_RELATION);
3635 
3636  /*
3637  * The qpqual list must contain all restrictions not enforced by the
3638  * tidrangequals list. tidrangequals has AND semantics, so we can simply
3639  * remove any qual that appears in it.
3640  */
3641  {
3642  List *qpqual = NIL;
3643  ListCell *l;
3644 
3645  foreach(l, scan_clauses)
3646  {
3647  RestrictInfo *rinfo = lfirst_node(RestrictInfo, l);
3648 
3649  if (rinfo->pseudoconstant)
3650  continue; /* we may drop pseudoconstants here */
3651  if (list_member_ptr(tidrangequals, rinfo))
3652  continue; /* simple duplicate */
3653  qpqual = lappend(qpqual, rinfo);
3654  }
3655  scan_clauses = qpqual;
3656  }
3657 
3658  /* Sort clauses into best execution order */
3659  scan_clauses = order_qual_clauses(root, scan_clauses);
3660 
3661  /* Reduce RestrictInfo lists to bare expressions; ignore pseudoconstants */
3662  tidrangequals = extract_actual_clauses(tidrangequals, false);
3663  scan_clauses = extract_actual_clauses(scan_clauses, false);
3664 
3665  /* Replace any outer-relation variables with nestloop params */
3666  if (best_path->path.param_info)
3667  {
3668  tidrangequals = (List *)
3669  replace_nestloop_params(root, (Node *) tidrangequals);
3670  scan_clauses = (List *)
3671  replace_nestloop_params(root, (Node *) scan_clauses);
3672  }
3673 
3674  scan_plan = make_tidrangescan(tlist,
3675  scan_clauses,
3676  scan_relid,
3677  tidrangequals);
3678 
3679  copy_generic_path_info(&scan_plan->scan.plan, &best_path->path);
3680 
3681  return scan_plan;
3682 }
3683 
3684 /*
3685  * create_subqueryscan_plan
3686  * Returns a subqueryscan plan for the base relation scanned by 'best_path'
3687  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3688  */
3689 static SubqueryScan *
3690 create_subqueryscan_plan(PlannerInfo *root, SubqueryScanPath *best_path,
3691  List *tlist, List *scan_clauses)
3692 {
3693  SubqueryScan *scan_plan;
3694  RelOptInfo *rel = best_path->path.parent;
3695  Index scan_relid = rel->relid;
3696  Plan *subplan;
3697 
3698  /* it should be a subquery base rel... */
3699  Assert(scan_relid > 0);
3700  Assert(rel->rtekind == RTE_SUBQUERY);
3701 
3702  /*
3703  * Recursively create Plan from Path for subquery. Since we are entering
3704  * a different planner context (subroot), recurse to create_plan not
3705  * create_plan_recurse.
3706  */
3707  subplan = create_plan(rel->subroot, best_path->subpath);
3708 
3709  /* Sort clauses into best execution order */
3710  scan_clauses = order_qual_clauses(root, scan_clauses);
3711 
3712  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3713  scan_clauses = extract_actual_clauses(scan_clauses, false);
3714 
3715  /* Replace any outer-relation variables with nestloop params */
3716  if (best_path->path.param_info)
3717  {
3718  scan_clauses = (List *)
3719  replace_nestloop_params(root, (Node *) scan_clauses);
3720  process_subquery_nestloop_params(root,
3721  rel->subplan_params);
3722  }
3723 
3724  scan_plan = make_subqueryscan(tlist,
3725  scan_clauses,
3726  scan_relid,
3727  subplan);
3728 
3729  copy_generic_path_info(&scan_plan->scan.plan, &best_path->path);
3730 
3731  return scan_plan;
3732 }
3733 
3734 /*
3735  * create_functionscan_plan
3736  * Returns a functionscan plan for the base relation scanned by 'best_path'
3737  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3738  */
3739 static FunctionScan *
3740 create_functionscan_plan(PlannerInfo *root, Path *best_path,
3741  List *tlist, List *scan_clauses)
3742 {
3743  FunctionScan *scan_plan;
3744  Index scan_relid = best_path->parent->relid;
3745  RangeTblEntry *rte;
3746  List *functions;
3747 
3748  /* it should be a function base rel... */
3749  Assert(scan_relid > 0);
3750  rte = planner_rt_fetch(scan_relid, root);
3751  Assert(rte->rtekind == RTE_FUNCTION);
3752  functions = rte->functions;
3753 
3754  /* Sort clauses into best execution order */
3755  scan_clauses = order_qual_clauses(root, scan_clauses);
3756 
3757  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3758  scan_clauses = extract_actual_clauses(scan_clauses, false);
3759 
3760  /* Replace any outer-relation variables with nestloop params */
3761  if (best_path->param_info)
3762  {
3763  scan_clauses = (List *)
3764  replace_nestloop_params(root, (Node *) scan_clauses);
3765  /* The function expressions could contain nestloop params, too */
3766  functions = (List *) replace_nestloop_params(root, (Node *) functions);
3767  }
3768 
3769  scan_plan = make_functionscan(tlist, scan_clauses, scan_relid,
3770  functions, rte->funcordinality);
3771 
3772  copy_generic_path_info(&scan_plan->scan.plan, best_path);
3773 
3774  return scan_plan;
3775 }
3776 
3777 /*
3778  * create_tablefuncscan_plan
3779  * Returns a tablefuncscan plan for the base relation scanned by 'best_path'
3780  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3781  */
3782 static TableFuncScan *
3783 create_tablefuncscan_plan(PlannerInfo *root, Path *best_path,
3784  List *tlist, List *scan_clauses)
3785 {
3786  TableFuncScan *scan_plan;
3787  Index scan_relid = best_path->parent->relid;
3788  RangeTblEntry *rte;
3789  TableFunc *tablefunc;
3790 
3791  /* it should be a function base rel... */
3792  Assert(scan_relid > 0);
3793  rte = planner_rt_fetch(scan_relid, root);
3794  Assert(rte->rtekind == RTE_TABLEFUNC);
3795  tablefunc = rte->tablefunc;
3796 
3797  /* Sort clauses into best execution order */
3798  scan_clauses = order_qual_clauses(root, scan_clauses);
3799 
3800  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3801  scan_clauses = extract_actual_clauses(scan_clauses, false);
3802 
3803  /* Replace any outer-relation variables with nestloop params */
3804  if (best_path->param_info)
3805  {
3806  scan_clauses = (List *)
3807  replace_nestloop_params(root, (Node *) scan_clauses);
3808  /* The function expressions could contain nestloop params, too */
3809  tablefunc = (TableFunc *) replace_nestloop_params(root, (Node *) tablefunc);
3810  }
3811 
3812  scan_plan = make_tablefuncscan(tlist, scan_clauses, scan_relid,
3813  tablefunc);
3814 
3815  copy_generic_path_info(&scan_plan->scan.plan, best_path);
3816 
3817  return scan_plan;
3818 }
3819 
3820 /*
3821  * create_valuesscan_plan
3822  * Returns a valuesscan plan for the base relation scanned by 'best_path'
3823  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3824  */
3825 static ValuesScan *
3826 create_valuesscan_plan(PlannerInfo *root, Path *best_path,
3827  List *tlist, List *scan_clauses)
3828 {
3829  ValuesScan *scan_plan;
3830  Index scan_relid = best_path->parent->relid;
3831  RangeTblEntry *rte;
3832  List *values_lists;
3833 
3834  /* it should be a values base rel... */
3835  Assert(scan_relid > 0);
3836  rte = planner_rt_fetch(scan_relid, root);
3837  Assert(rte->rtekind == RTE_VALUES);
3838  values_lists = rte->values_lists;
3839 
3840  /* Sort clauses into best execution order */
3841  scan_clauses = order_qual_clauses(root, scan_clauses);
3842 
3843  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3844  scan_clauses = extract_actual_clauses(scan_clauses, false);
3845 
3846  /* Replace any outer-relation variables with nestloop params */
3847  if (best_path->param_info)
3848  {
3849  scan_clauses = (List *)
3850  replace_nestloop_params(root, (Node *) scan_clauses);
3851  /* The values lists could contain nestloop params, too */
3852  values_lists = (List *)
3853  replace_nestloop_params(root, (Node *) values_lists);
3854  }
3855 
3856  scan_plan = make_valuesscan(tlist, scan_clauses, scan_relid,
3857  values_lists);
3858 
3859  copy_generic_path_info(&scan_plan->scan.plan, best_path);
3860 
3861  return scan_plan;
3862 }
3863 
3864 /*
3865  * create_ctescan_plan
3866  * Returns a ctescan plan for the base relation scanned by 'best_path'
3867  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
3868  */
3869 static CteScan *
3870 create_ctescan_plan(PlannerInfo *root, Path *best_path,
3871  List *tlist, List *scan_clauses)
3872 {
3873  CteScan *scan_plan;
3874  Index scan_relid = best_path->parent->relid;
3875  RangeTblEntry *rte;
3876  SubPlan *ctesplan = NULL;
3877  int plan_id;
3878  int cte_param_id;
3879  PlannerInfo *cteroot;
3880  Index levelsup;
3881  int ndx;
3882  ListCell *lc;
3883 
3884  Assert(scan_relid > 0);
3885  rte = planner_rt_fetch(scan_relid, root);
3886  Assert(rte->rtekind == RTE_CTE);
3887  Assert(!rte->self_reference);
3888 
3889  /*
3890  * Find the referenced CTE, and locate the SubPlan previously made for it.
3891  */
3892  levelsup = rte->ctelevelsup;
3893  cteroot = root;
3894  while (levelsup-- > 0)
3895  {
3896  cteroot = cteroot->parent_root;
3897  if (!cteroot) /* shouldn't happen */
3898  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
3899  }
3900 
3901  /*
3902  * Note: cte_plan_ids can be shorter than cteList, if we are still working
3903  * on planning the CTEs (ie, this is a side-reference from another CTE).
3904  * So we mustn't use forboth here.
3905  */
3906  ndx = 0;
3907  foreach(lc, cteroot->parse->cteList)
3908  {
3909  CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
3910 
3911  if (strcmp(cte->ctename, rte->ctename) == 0)
3912  break;
3913  ndx++;
3914  }
3915  if (lc == NULL) /* shouldn't happen */
3916  elog(ERROR, "could not find CTE \"%s\"", rte->ctename);
3917  if (ndx >= list_length(cteroot->cte_plan_ids))
3918  elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
3919  plan_id = list_nth_int(cteroot->cte_plan_ids, ndx);
3920  if (plan_id <= 0)
3921  elog(ERROR, "no plan was made for CTE \"%s\"", rte->ctename);
3922  foreach(lc, cteroot->init_plans)
3923  {
3924  ctesplan = (SubPlan *) lfirst(lc);
3925  if (ctesplan->plan_id == plan_id)
3926  break;
3927  }
3928  if (lc == NULL) /* shouldn't happen */
3929  elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
3930 
3931  /*
3932  * We need the CTE param ID, which is the sole member of the SubPlan's
3933  * setParam list.
3934  */
3935  cte_param_id = linitial_int(ctesplan->setParam);
3936 
3937  /* Sort clauses into best execution order */
3938  scan_clauses = order_qual_clauses(root, scan_clauses);
3939 
3940  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3941  scan_clauses = extract_actual_clauses(scan_clauses, false);
3942 
3943  /* Replace any outer-relation variables with nestloop params */
3944  if (best_path->param_info)
3945  {
3946  scan_clauses = (List *)
3947  replace_nestloop_params(root, (Node *) scan_clauses);
3948  }
3949 
3950  scan_plan = make_ctescan(tlist, scan_clauses, scan_relid,
3951  plan_id, cte_param_id);
3952 
3953  copy_generic_path_info(&scan_plan->scan.plan, best_path);
3954 
3955  return scan_plan;
3956 }
3957 
3958 /*
3959  * create_namedtuplestorescan_plan
3960  * Returns a tuplestorescan plan for the base relation scanned by
3961  * 'best_path' with restriction clauses 'scan_clauses' and targetlist
3962  * 'tlist'.
3963  */
3964 static NamedTuplestoreScan *
3965 create_namedtuplestorescan_plan(PlannerInfo *root, Path *best_path,
3966  List *tlist, List *scan_clauses)
3967 {
3968  NamedTuplestoreScan *scan_plan;
3969  Index scan_relid = best_path->parent->relid;
3970  RangeTblEntry *rte;
3971 
3972  Assert(scan_relid > 0);
3973  rte = planner_rt_fetch(scan_relid, root);
3974  Assert(rte->rtekind == RTE_NAMEDTUPLESTORE);
3975 
3976  /* Sort clauses into best execution order */
3977  scan_clauses = order_qual_clauses(root, scan_clauses);
3978 
3979  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
3980  scan_clauses = extract_actual_clauses(scan_clauses, false);
3981 
3982  /* Replace any outer-relation variables with nestloop params */
3983  if (best_path->param_info)
3984  {
3985  scan_clauses = (List *)
3986  replace_nestloop_params(root, (Node *) scan_clauses);
3987  }
3988 
3989  scan_plan = make_namedtuplestorescan(tlist, scan_clauses, scan_relid,
3990  rte->enrname);
3991 
3992  copy_generic_path_info(&scan_plan->scan.plan, best_path);
3993 
3994  return scan_plan;
3995 }
3996 
3997 /*
3998  * create_resultscan_plan
3999  * Returns a Result plan for the RTE_RESULT base relation scanned by
4000  * 'best_path' with restriction clauses 'scan_clauses' and targetlist
4001  * 'tlist'.
4002  */
4003 static Result *
4004 create_resultscan_plan(PlannerInfo *root, Path *best_path,
4005  List *tlist, List *scan_clauses)
4006 {
4007  Result *scan_plan;
4008  Index scan_relid = best_path->parent->relid;
4009  RangeTblEntry *rte PG_USED_FOR_ASSERTS_ONLY;
4010 
4011  Assert(scan_relid > 0);
4012  rte = planner_rt_fetch(scan_relid, root);
4013  Assert(rte->rtekind == RTE_RESULT);
4014 
4015  /* Sort clauses into best execution order */
4016  scan_clauses = order_qual_clauses(root, scan_clauses);
4017 
4018  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
4019  scan_clauses = extract_actual_clauses(scan_clauses, false);
4020 
4021  /* Replace any outer-relation variables with nestloop params */
4022  if (best_path->param_info)
4023  {
4024  scan_clauses = (List *)
4025  replace_nestloop_params(root, (Node *) scan_clauses);
4026  }
4027 
4028  scan_plan = make_result(tlist, (Node *) scan_clauses, NULL);
4029 
4030  copy_generic_path_info(&scan_plan->plan, best_path);
4031 
4032  return scan_plan;
4033 }
4034 
4035 /*
4036  * create_worktablescan_plan
4037  * Returns a worktablescan plan for the base relation scanned by 'best_path'
4038  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
4039  */
4040 static WorkTableScan *
4041 create_worktablescan_plan(PlannerInfo *root, Path *best_path,
4042  List *tlist, List *scan_clauses)
4043 {
4044  WorkTableScan *scan_plan;
4045  Index scan_relid = best_path->parent->relid;
4046  RangeTblEntry *rte;
4047  Index levelsup;
4048  PlannerInfo *cteroot;
4049 
4050  Assert(scan_relid > 0);
4051  rte = planner_rt_fetch(scan_relid, root);
4052  Assert(rte->rtekind == RTE_CTE);
4053  Assert(rte->self_reference);
4054 
4055  /*
4056  * We need to find the worktable param ID, which is in the plan level
4057  * that's processing the recursive UNION, which is one level *below* where
4058  * the CTE comes from.
4059  */
4060  levelsup = rte->ctelevelsup;
4061  if (levelsup == 0) /* shouldn't happen */
4062  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
4063  levelsup--;
4064  cteroot = root;
4065  while (levelsup-- > 0)
4066  {
4067  cteroot = cteroot->parent_root;
4068  if (!cteroot) /* shouldn't happen */
4069  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
4070  }
4071  if (cteroot->wt_param_id < 0) /* shouldn't happen */
4072  elog(ERROR, "could not find param ID for CTE \"%s\"", rte->ctename);
4073 
4074  /* Sort clauses into best execution order */
4075  scan_clauses = order_qual_clauses(root, scan_clauses);
4076 
4077  /* Reduce RestrictInfo list to bare expressions; ignore pseudoconstants */
4078  scan_clauses = extract_actual_clauses(scan_clauses, false);
4079 
4080  /* Replace any outer-relation variables with nestloop params */
4081  if (best_path->param_info)
4082  {
4083  scan_clauses = (List *)
4084  replace_nestloop_params(root, (Node *) scan_clauses);
4085  }
4086 
4087  scan_plan = make_worktablescan(tlist, scan_clauses, scan_relid,
4088  cteroot->wt_param_id);
4089 
4090  copy_generic_path_info(&scan_plan->scan.plan, best_path);
4091 
4092  return scan_plan;
4093 }
4094 
4095 /*
4096  * create_foreignscan_plan
4097  * Returns a foreignscan plan for the relation scanned by 'best_path'
4098  * with restriction clauses 'scan_clauses' and targetlist 'tlist'.
4099  */
4100 static ForeignScan *
4101 create_foreignscan_plan(PlannerInfo *root, ForeignPath *best_path,
4102  List *tlist, List *scan_clauses)
4103 {
4104  ForeignScan *scan_plan;
4105  RelOptInfo *rel = best_path->path.parent;
4106  Index scan_relid = rel->relid;
4107  Oid rel_oid = InvalidOid;
4108  Plan *outer_plan = NULL;
4109 
4110  Assert(rel->fdwroutine != NULL);
4111 
4112  /* transform the child path if any */
4113  if (best_path->fdw_outerpath)
4114  outer_plan = create_plan_recurse(root, best_path->fdw_outerpath,
4115  CP_EXACT_TLIST);
4116 
4117  /*
4118  * If we're scanning a base relation, fetch its OID. (Irrelevant if
4119  * scanning a join relation.)
4120  */
4121  if (scan_relid > 0)
4122  {
4123  RangeTblEntry *rte;
4124 
4125  Assert(rel->rtekind == RTE_RELATION);
4126  rte = planner_rt_fetch(scan_relid, root);
4127  Assert(rte->rtekind == RTE_RELATION);
4128  rel_oid = rte->relid;
4129  }
4130 
4131  /*
4132  * Sort clauses into best execution order. We do this first since the FDW
4133  * might have more info than we do and wish to adjust the ordering.
4134  */
4135  scan_clauses = order_qual_clauses(root, scan_clauses);
4136 
4137  /*
4138  * Let the FDW perform its processing on the restriction clauses and
4139  * generate the plan node. Note that the FDW might remove restriction
4140  * clauses that it intends to execute remotely, or even add more (if it
4141  * has selected some join clauses for remote use but also wants them
4142  * rechecked locally).
4143  */
4144  scan_plan = rel->fdwroutine->GetForeignPlan(root, rel, rel_oid,
4145  best_path,
4146  tlist, scan_clauses,
4147  outer_plan);
4148 
4149  /* Copy cost data from Path to Plan; no need to make FDW do this */
4150  copy_generic_path_info(&scan_plan->scan.plan, &best_path->path);
4151 
4152  /* Copy foreign server OID; likewise, no need to make FDW do this */
4153  scan_plan->fs_server = rel->serverid;
4154 
4155  /*
4156  * Likewise, copy the relids that are represented by this foreign scan. An
4157  * upper rel doesn't have relids set, but it covers all the base relations
4158  * participating in the underlying scan, so use root's all_baserels.
4159  */
4160  if (rel->reloptkind == RELOPT_UPPER_REL)
4161  scan_plan->fs_relids = root->all_baserels;
4162  else
4163  scan_plan->fs_relids = best_path->path.parent->relids;
4164 
4165  /*
4166  * If this is a foreign join, and to make it valid to push down we had to
4167  * assume that the current user is the same as some user explicitly named
4168  * in the query, mark the finished plan as depending on the current user.
4169  */
4170  if (rel->useridiscurrent)
4171  root->glob->dependsOnRole = true;
4172 
4173  /*
4174  * Replace any outer-relation variables with nestloop params in the qual,
4175  * fdw_exprs and fdw_recheck_quals expressions. We do this last so that
4176  * the FDW doesn't have to be involved. (Note that parts of fdw_exprs or
4177  * fdw_recheck_quals could have come from join clauses, so doing this
4178  * beforehand on the scan_clauses wouldn't work.) We assume
4179  * fdw_scan_tlist contains no such variables.
4180  */
4181  if (best_path->path.param_info)
4182  {
4183  scan_plan->scan.plan.qual = (List *)
4184  replace_nestloop_params(root, (Node *) scan_plan->scan.plan.qual);
4185  scan_plan->fdw_exprs = (List *)
4186  replace_nestloop_params(root, (Node *) scan_plan->fdw_exprs);
4187  scan_plan->fdw_recheck_quals = (List *)
4188  replace_nestloop_params(root,
4189  (Node *) scan_plan->fdw_recheck_quals);
4190  }
4191 
4192  /*
4193  * If rel is a base relation, detect whether any system columns are
4194  * requested from the rel. (If rel is a join relation, rel->relid will be
4195  * 0, but there can be no Var with relid 0 in the rel's targetlist or the
4196  * restriction clauses, so we skip this in that case. Note that any such
4197  * columns in base relations that were joined are assumed to be contained
4198  * in fdw_scan_tlist.) This is a bit of a kluge and might go away
4199  * someday, so we intentionally leave it out of the API presented to FDWs.
4200  */
4201  scan_plan->fsSystemCol = false;
4202  if (scan_relid > 0)
4203  {
4204  Bitmapset *attrs_used = NULL;
4205  ListCell *lc;
4206  int i;
4207 
4208  /*
4209  * First, examine all the attributes needed for joins or final output.
4210  * Note: we must look at rel's targetlist, not the attr_needed data,
4211  * because attr_needed isn't computed for inheritance child rels.
4212  */
4213  pull_varattnos((Node *) rel->reltarget->exprs, scan_relid, &attrs_used);
4214 
4215  /* Add all the attributes used by restriction clauses. */
4216  foreach(lc, rel->baserestrictinfo)
4217  {
4218  RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
4219 
4220  pull_varattnos((Node *) rinfo->clause, scan_relid, &attrs_used);
4221  }
4222 
4223  /* Now, are any system columns requested from rel? */
4224  for (i = FirstLowInvalidHeapAttributeNumber + 1; i < 0; i++)
4225  {
4226  if (bms_is_member(i - FirstLowInvalidHeapAttributeNumber, attrs_used))
4227  {
4228  scan_plan->fsSystemCol = true;
4229  break;
4230  }
4231  }
4232 
4233  bms_free(attrs_used);
4234  }
4235 
4236  return scan_plan;
4237 }
4238 
4239 /*
4240  * create_customscan_plan
4241  *
4242  * Transform a CustomPath into a Plan.
4243  */
4244 static CustomScan *
4245 create_customscan_plan(PlannerInfo *root, CustomPath *best_path,
4246  List *tlist, List *scan_clauses)
4247 {
4248  CustomScan *cplan;
4249  RelOptInfo *rel = best_path->path.parent;
4250  List *custom_plans = NIL;
4251  ListCell *lc;
4252 
4253  /* Recursively transform child paths. */
4254  foreach(lc, best_path->custom_paths)
4255  {
4256  Plan *plan = create_plan_recurse(root, (Path *) lfirst(lc),
4257  CP_EXACT_TLIST);
4258 
4259  custom_plans = lappend(custom_plans, plan);
4260  }
4261 
4262  /*
4263  * Sort clauses into the best execution order, although custom-scan
4264  * provider can reorder them again.
4265  */
4266  scan_clauses = order_qual_clauses(root, scan_clauses);
4267 
4268  /*
4269  * Invoke custom plan provider to create the Plan node represented by the
4270  * CustomPath.
4271  */
4272  cplan = castNode(CustomScan,
4273  best_path->methods->PlanCustomPath(root,
4274  rel,
4275  best_path,
4276  tlist,
4277  scan_clauses,
4278  custom_plans));
4279 
4280  /*
4281  * Copy cost data from Path to Plan; no need to make custom-plan providers
4282  * do this
4283  */
4284  copy_generic_path_info(&cplan->scan.plan, &best_path->path);
4285 
4286  /* Likewise, copy the relids that are represented by this custom scan */
4287  cplan->custom_relids = best_path->path.parent->relids;
4288 
4289  /*
4290  * Replace any outer-relation variables with nestloop params in the qual
4291  * and custom_exprs expressions. We do this last so that the custom-plan
4292  * provider doesn't have to be involved. (Note that parts of custom_exprs
4293  * could have come from join clauses, so doing this beforehand on the
4294  * scan_clauses wouldn't work.) We assume custom_scan_tlist contains no
4295  * such variables.
4296  */
4297  if (best_path->path.param_info)
4298  {
4299  cplan->scan.plan.qual = (List *)
4300  replace_nestloop_params(root, (Node *) cplan->scan.plan.qual);
4301  cplan->custom_exprs = (List *)
4302  replace_nestloop_params(root, (Node *) cplan->custom_exprs);
4303  }
4304 
4305  return cplan;
4306 }
4307 
4308 
4309 /*****************************************************************************
4310  *
4311  * JOIN METHODS
4312  *
4313  *****************************************************************************/
4314 
4315 static NestLoop *
4316 create_nestloop_plan(PlannerInfo *root,
4317  NestPath *best_path)
4318 {
4319  NestLoop *join_plan;
4320  Plan *outer_plan;
4321  Plan *inner_plan;
4322  List *tlist = build_path_tlist(root, &best_path->jpath.path);
4323  List *joinrestrictclauses = best_path->jpath.joinrestrictinfo;
4324  List *joinclauses;
4325  List *otherclauses;
4326  Relids outerrelids;
4327  List *nestParams;
4328  Relids saveOuterRels = root->curOuterRels;
4329 
4330  /* NestLoop can project, so no need to be picky about child tlists */
4331  outer_plan = create_plan_recurse(root, best_path->jpath.outerjoinpath, 0);
4332 
4333  /* For a nestloop, include outer relids in curOuterRels for inner side */
4334  root->curOuterRels = bms_union(root->curOuterRels,
4335  best_path->jpath.outerjoinpath->parent->relids);
4336 
4337  inner_plan = create_plan_recurse(root, best_path->jpath.innerjoinpath, 0);
4338 
4339  /* Restore curOuterRels */
4340  bms_free(root->curOuterRels);
4341  root->curOuterRels = saveOuterRels;
4342 
4343  /* Sort join qual clauses into best execution order */
4344  joinrestrictclauses = order_qual_clauses(root, joinrestrictclauses);
4345 
4346  /* Get the join qual clauses (in plain expression form) */
4347  /* Any pseudoconstant clauses are ignored here */
4348  if (IS_OUTER_JOIN(best_path->jpath.jointype))
4349  {
4350  extract_actual_join_clauses(joinrestrictclauses,
4351  best_path->jpath.path.parent->relids,
4352  &joinclauses, &otherclauses);
4353  }
4354  else
4355  {
4356  /* We can treat all clauses alike for an inner join */
4357  joinclauses = extract_actual_clauses(joinrestrictclauses, false);
4358  otherclauses = NIL;
4359  }
4360 
4361  /* Replace any outer-relation variables with nestloop params */
4362  if (best_path->jpath.path.param_info)
4363  {
4364  joinclauses = (List *)
4365  replace_nestloop_params(root, (Node *) joinclauses);
4366  otherclauses = (List *)
4367  replace_nestloop_params(root, (Node *) otherclauses);
4368  }
4369 
4370  /*
4371  * Identify any nestloop parameters that should be supplied by this join
4372  * node, and remove them from root->curOuterParams.
4373  */
4374  outerrelids = best_path->jpath.outerjoinpath->parent->relids;
4375  nestParams = identify_current_nestloop_params(root, outerrelids);
4376 
4377  join_plan = make_nestloop(tlist,
4378  joinclauses,
4379  otherclauses,
4380  nestParams,
4381  outer_plan,
4382  inner_plan,
4383  best_path->jpath.jointype,
4384  best_path->jpath.inner_unique);
4385 
4386  copy_generic_path_info(&join_plan->join.plan, &best_path->jpath.path);
4387 
4388  return join_plan;
4389 }
4390 
4391 static MergeJoin *
4392 create_mergejoin_plan(PlannerInfo *root,
4393  MergePath *best_path)
4394 {
4395  MergeJoin *join_plan;
4396  Plan *outer_plan;
4397  Plan *inner_plan;
4398  List *tlist = build_path_tlist(root, &best_path->jpath.path);
4399  List *joinclauses;
4400  List *otherclauses;
4401  List *mergeclauses;
4402  List *outerpathkeys;
4403  List *innerpathkeys;
4404  int nClauses;
4405  Oid *mergefamilies;
4406  Oid *mergecollations;
4407  int *mergestrategies;
4408  bool *mergenullsfirst;
4409  PathKey *opathkey;
4410  EquivalenceClass *opeclass;
4411  int i;
4412  ListCell *lc;
4413  ListCell *lop;
4414  ListCell *lip;
4415  Path *outer_path = best_path->jpath.outerjoinpath;
4416  Path *inner_path = best_path->jpath.innerjoinpath;
4417 
4418  /*
4419  * MergeJoin can project, so we don't have to demand exact tlists from the
4420  * inputs. However, if we're intending to sort an input's result, it's
4421  * best to request a small tlist so we aren't sorting more data than
4422  * necessary.
4423  */
4424  outer_plan = create_plan_recurse(root, best_path->jpath.outerjoinpath,
4425  (best_path->outersortkeys != NIL) ? CP_SMALL_TLIST : 0);
4426 
4427  inner_plan = create_plan_recurse(root, best_path->jpath.innerjoinpath,
4428  (best_path->innersortkeys != NIL) ? CP_SMALL_TLIST : 0);
4429 
4430  /* Sort join qual clauses into best execution order */
4431  /* NB: do NOT reorder the mergeclauses */
4432  joinclauses = order_qual_clauses(root, best_path->jpath.joinrestrictinfo);
4433 
4434  /* Get the join qual clauses (in plain expression form) */
4435  /* Any pseudoconstant clauses are ignored here */
4436  if (IS_OUTER_JOIN(best_path->jpath.jointype))
4437  {
4438  extract_actual_join_clauses(joinclauses,
4439  best_path->jpath.path.parent->relids,
4440  &joinclauses, &otherclauses);
4441  }
4442  else
4443  {
4444  /* We can treat all clauses alike for an inner join */
4445  joinclauses = extract_actual_clauses(joinclauses, false);
4446  otherclauses = NIL;
4447  }
4448 
4449  /*
4450  * Remove the mergeclauses from the list of join qual clauses, leaving the
4451  * list of quals that must be checked as qpquals.
4452  */
4453  mergeclauses = get_actual_clauses(best_path->path_mergeclauses);
4454  joinclauses = list_difference(joinclauses, mergeclauses);
4455 
4456  /*
4457  * Replace any outer-relation variables with nestloop params. There
4458  * should not be any in the mergeclauses.
4459  */
4460  if (best_path->jpath.path.param_info)
4461  {
4462  joinclauses = (List *)
4463  replace_nestloop_params(root, (Node *) joinclauses);
4464  otherclauses = (List *)
4465  replace_nestloop_params(root, (Node *) otherclauses);
4466  }
4467 
4468  /*
4469  * Rearrange mergeclauses, if needed, so that the outer variable is always
4470  * on the left; mark the mergeclause restrictinfos with correct
4471  * outer_is_left status.
4472  */
4473  mergeclauses = get_switched_clauses(best_path->path_mergeclauses,
4474  best_path->jpath.outerjoinpath->parent->relids);
4475 
4476  /*
4477  * Create explicit sort nodes for the outer and inner paths if necessary.
4478  */
4479  if (best_path->outersortkeys)
4480  {
4481  Relids outer_relids = outer_path->parent->relids;
4482  Sort *sort = make_sort_from_pathkeys(outer_plan,
4483  best_path->outersortkeys,
4484  outer_relids);
4485 
4486  label_sort_with_costsize(root, sort, -1.0);
4487  outer_plan = (Plan *) sort;
4488  outerpathkeys = best_path->outersortkeys;
4489  }
4490  else
4491  outerpathkeys = best_path->jpath.outerjoinpath->pathkeys;
4492 
4493  if (best_path->innersortkeys)
4494  {
4495  Relids inner_relids = inner_path->parent->relids;
4496  Sort *sort = make_sort_from_pathkeys(inner_plan,
4497  best_path->innersortkeys,
4498  inner_relids);
4499 
4500  label_sort_with_costsize(root, sort, -1.0);
4501  inner_plan = (Plan *) sort;
4502  innerpathkeys = best_path->innersortkeys;
4503  }
4504  else
4505  innerpathkeys = best_path->jpath.innerjoinpath->pathkeys;
4506 
4507  /*
4508  * If specified, add a materialize node to shield the inner plan from the
4509  * need to handle mark/restore.
4510  */
4511  if (best_path->materialize_inner)
4512  {
4513  Plan *matplan = (Plan *) make_material(inner_plan);
4514 
4515  /*
4516  * We assume the materialize will not spill to disk, and therefore
4517  * charge just cpu_operator_cost per tuple. (Keep this estimate in
4518  * sync with final_cost_mergejoin.)
4519  */
4520  copy_plan_costsize(matplan, inner_plan);
4521  matplan->total_cost += cpu_operator_cost * matplan->plan_rows;
4522 
4523  inner_plan = matplan;
4524  }
4525 
4526  /*
4527  * Compute the opfamily/collation/strategy/nullsfirst arrays needed by the
4528  * executor. The information is in the pathkeys for the two inputs, but
4529  * we need to be careful about the possibility of mergeclauses sharing a
4530  * pathkey, as well as the possibility that the inner pathkeys are not in
4531  * an order matching the mergeclauses.
4532  */
4533  nClauses = list_length(mergeclauses);
4534  Assert(nClauses == list_length(best_path->path_mergeclauses));
4535  mergefamilies = (Oid *) palloc(nClauses * sizeof(Oid));
4536  mergecollations = (Oid *) palloc(nClauses * sizeof(Oid));
4537  mergestrategies = (int *) palloc(nClauses * sizeof(int));
4538  mergenullsfirst = (bool *) palloc(nClauses * sizeof(bool));
4539 
4540  opathkey = NULL;
4541  opeclass = NULL;
4542  lop = list_head(outerpathkeys);
4543  lip = list_head(innerpathkeys);
4544  i = 0;
4545  foreach(lc, best_path->path_mergeclauses)
4546  {
4547  RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
4548  EquivalenceClass *oeclass;
4549  EquivalenceClass *ieclass;
4550  PathKey *ipathkey = NULL;
4551  EquivalenceClass *ipeclass = NULL;
4552  bool first_inner_match = false;
4553 
4554  /* fetch outer/inner eclass from mergeclause */
4555  if (rinfo->outer_is_left)
4556  {
4557  oeclass = rinfo->left_ec;
4558  ieclass = rinfo->right_ec;
4559  }
4560  else
4561  {
4562  oeclass = rinfo->right_ec;
4563  ieclass = rinfo->left_ec;
4564  }
4565  Assert(oeclass != NULL);
4566  Assert(ieclass != NULL);
4567 
4568  /*
4569  * We must identify the pathkey elements associated with this clause
4570  * by matching the eclasses (which should give a unique match, since
4571  * the pathkey lists should be canonical). In typical cases the merge
4572  * clauses are one-to-one with the pathkeys, but when dealing with
4573  * partially redundant query conditions, things are more complicated.
4574  *
4575  * lop and lip reference the first as-yet-unmatched pathkey elements.
4576  * If they're NULL then all pathkey elements have been matched.
4577  *
4578  * The ordering of the outer pathkeys should match the mergeclauses,
4579  * by construction (see find_mergeclauses_for_outer_pathkeys()). There
4580  * could be more than one mergeclause for the same outer pathkey, but
4581  * no pathkey may be entirely skipped over.
4582  */
4583  if (oeclass != opeclass) /* multiple matches are not interesting */
4584  {
4585  /* doesn't match the current opathkey, so must match the next */
4586  if (lop == NULL)
4587  elog(ERROR, "outer pathkeys do not match mergeclauses");
4588  opathkey = (PathKey *) lfirst(lop);
4589  opeclass = opathkey->pk_eclass;
4590  lop = lnext(outerpathkeys, lop);
4591  if (oeclass != opeclass)
4592  elog(ERROR, "outer pathkeys do not match mergeclauses");
4593  }
4594 
4595  /*
4596  * The inner pathkeys likewise should not have skipped-over keys, but
4597  * it's possible for a mergeclause to reference some earlier inner
4598  * pathkey if we had redundant pathkeys. For example we might have
4599  * mergeclauses like "o.a = i.x AND o.b = i.y AND o.c = i.x". The
4600  * implied inner ordering is then "ORDER BY x, y, x", but the pathkey
4601  * mechanism drops the second sort by x as redundant, and this code
4602  * must cope.
4603  *
4604  * It's also possible for the implied inner-rel ordering to be like
4605  * "ORDER BY x, y, x DESC". We still drop the second instance of x as
4606  * redundant; but this means that the sort ordering of a redundant
4607  * inner pathkey should not be considered significant. So we must
4608  * detect whether this is the first clause matching an inner pathkey.
4609  */
4610  if (lip)
4611  {
4612  ipathkey = (PathKey *) lfirst(lip);
4613  ipeclass = ipathkey->pk_eclass;
4614  if (ieclass == ipeclass)
4615  {
4616  /* successful first match to this inner pathkey */
4617  lip = lnext(innerpathkeys, lip);
4618  first_inner_match = true;
4619  }
4620  }
4621  if (!first_inner_match)
4622  {
4623  /* redundant clause ... must match something before lip */
4624  ListCell *l2;
4625 
4626  foreach(l2, innerpathkeys)
4627  {
4628  if (l2 == lip)
4629  break;
4630  ipathkey = (PathKey *) lfirst(l2);
4631  ipeclass = ipathkey->pk_eclass;
4632  if (ieclass == ipeclass)
4633  break;
4634  }
4635  if (ieclass != ipeclass)
4636  elog(ERROR, "inner pathkeys do not match mergeclauses");
4637  }
4638 
4639  /*
4640  * The pathkeys should always match each other as to opfamily and
4641  * collation (which affect equality), but if we're considering a
4642  * redundant inner pathkey, its sort ordering might not match. In
4643  * such cases we may ignore the inner pathkey's sort ordering and use
4644  * the outer's. (In effect, we're lying to the executor about the
4645  * sort direction of this inner column, but it does not matter since
4646  * the run-time row comparisons would only reach this column when
4647  * there's equality for the earlier column containing the same eclass.
4648  * There could be only one value in this column for the range of inner
4649  * rows having a given value in the earlier column, so it does not
4650  * matter which way we imagine this column to be ordered.) But a
4651  * non-redundant inner pathkey had better match outer's ordering too.
4652  */
4653  if (opathkey->pk_opfamily != ipathkey->pk_opfamily ||
4654  opathkey->pk_eclass->ec_collation != ipathkey->pk_eclass->ec_collation)
4655  elog(ERROR, "left and right pathkeys do not match in mergejoin");
4656  if (first_inner_match &&
4657  (opathkey->pk_strategy != ipathkey->pk_strategy ||
4658  opathkey->pk_nulls_first != ipathkey->pk_nulls_first))
4659  elog(ERROR, "left and right pathkeys do not match in mergejoin");
4660 
4661  /* OK, save info for executor */
4662  mergefamilies[i] = opathkey->pk_opfamily;
4663  mergecollations[i] = opathkey->pk_eclass->ec_collation;
4664  mergestrategies[i] = opathkey->pk_strategy;
4665  mergenullsfirst[i] = opathkey->pk_nulls_first;
4666  i++;
4667  }
4668 
4669  /*
4670  * Note: it is not an error if we have additional pathkey elements (i.e.,
4671  * lop or lip isn't NULL here). The input paths might be better-sorted
4672  * than we need for the current mergejoin.
4673  */
4674 
4675  /*
4676  * Now we can build the mergejoin node.
4677  */
4678  join_plan = make_mergejoin(tlist,
4679  joinclauses,
4680  otherclauses,
4681  mergeclauses,
4682  mergefamilies,
4683  mergecollations,
4684  mergestrategies,
4685  mergenullsfirst,
4686  outer_plan,
4687  inner_plan,
4688  best_path->jpath.jointype,
4689  best_path->jpath.inner_unique,
4690  best_path->skip_mark_restore);
4691 
4692  /* Costs of sort and material steps are included in path cost already */
4693  copy_generic_path_info(&join_plan->join.plan, &best_path->jpath.path);
4694 
4695  return join_plan;
4696 }
4697 
4698 static HashJoin *
4699 create_hashjoin_plan(PlannerInfo *root,
4700  HashPath *best_path)
4701 {
4702  HashJoin *join_plan;
4703  Hash *hash_plan;
4704  Plan *outer_plan;
4705  Plan *inner_plan;
4706  List *tlist = build_path_tlist(root, &best_path->jpath.path);
4707  List *joinclauses;
4708  List *otherclauses;
4709  List *hashclauses;
4710  List *hashoperators = NIL;
4711  List *hashcollations = NIL;
4712  List *inner_hashkeys = NIL;
4713  List *outer_hashkeys = NIL;
4714  Oid skewTable = InvalidOid;
4715  AttrNumber skewColumn = InvalidAttrNumber;
4716  bool skewInherit = false;
4717  ListCell *lc;
4718 
4719  /*
4720  * HashJoin can project, so we don't have to demand exact tlists from the
4721  * inputs. However, it's best to request a small tlist from the inner
4722  * side, so that we aren't storing more data than necessary. Likewise, if
4723  * we anticipate batching, request a small tlist from the outer side so
4724  * that we don't put extra data in the outer batch files.
4725  */
4726  outer_plan = create_plan_recurse(root, best_path->jpath.outerjoinpath,
4727  (best_path->num_batches > 1) ? CP_SMALL_TLIST : 0);
4728 
4729  inner_plan = create_plan_recurse(root, best_path->jpath.innerjoinpath,
4730  CP_SMALL_TLIST);
4731 
4732  /* Sort join qual clauses into best execution order */
4733  joinclauses = order_qual_clauses(root, best_path->jpath.joinrestrictinfo);
4734  /* There's no point in sorting the hash clauses ... */
4735 
4736  /* Get the join qual clauses (in plain expression form) */
4737  /* Any pseudoconstant clauses are ignored here */
4738  if (IS_OUTER_JOIN(best_path->jpath.jointype))
4739  {
4740  extract_actual_join_clauses(joinclauses,
4741  best_path->jpath.path.parent->relids,
4742  &joinclauses, &otherclauses);
4743  }
4744  else
4745  {
4746  /* We can treat all clauses alike for an inner join */
4747  joinclauses = extract_actual_clauses(joinclauses, false);
4748  otherclauses = NIL;
4749  }
4750 
4751  /*
4752  * Remove the hashclauses from the list of join qual clauses, leaving the
4753  * list of quals that must be checked as qpquals.
4754  */
4755  hashclauses = get_actual_clauses(best_path->path_hashclauses);
4756  joinclauses = list_difference(joinclauses, hashclauses);
4757 
4758  /*
4759  * Replace any outer-relation variables with nestloop params. There
4760  * should not be any in the hashclauses.
4761  */
4762  if (best_path->jpath.path.param_info)
4763  {
4764  joinclauses = (List *)
4765  replace_nestloop_params(root, (Node *) joinclauses);
4766  otherclauses = (List *)
4767  replace_nestloop_params(root, (Node *) otherclauses);
4768  }
4769 
4770  /*
4771  * Rearrange hashclauses, if needed, so that the outer variable is always
4772  * on the left.
4773  */
4774  hashclauses = get_switched_clauses(best_path->path_hashclauses,
4775  best_path->jpath.outerjoinpath->parent->relids);
4776 
4777  /*
4778  * If there is a single join clause and we can identify the outer variable
4779  * as a simple column reference, supply its identity for possible use in
4780  * skew optimization. (Note: in principle we could do skew optimization
4781  * with multiple join clauses, but we'd have to be able to determine the
4782  * most common combinations of outer values, which we don't currently have
4783  * enough stats for.)
4784  */
4785  if (list_length(hashclauses) == 1)
4786  {
4787  OpExpr *clause = (OpExpr *) linitial(hashclauses);
4788  Node *node;
4789 
4790  Assert(is_opclause(clause));
4791  node = (Node *) linitial(clause->args);
4792  if (IsA(node, RelabelType))
4793  node = (Node *) ((RelabelType *) node)->arg;
4794  if (IsA(node, Var))
4795  {
4796  Var *var = (Var *) node;
4797  RangeTblEntry *rte;
4798 
4799  rte = root->simple_rte_array[var->varno];
4800  if (rte->rtekind == RTE_RELATION)
4801  {
4802  skewTable = rte->relid;
4803  skewColumn = var->varattno;
4804  skewInherit = rte->inh;
4805  }
4806  }
4807  }
4808 
4809  /*
4810  * Collect hash related information. The hashed expressions are
4811  * deconstructed into outer/inner expressions, so they can be computed
4812  * separately (inner expressions are used to build the hashtable via Hash,
4813  * outer expressions to perform lookups of tuples from HashJoin's outer
4814  * plan in the hashtable). Also collect operator information necessary to
4815  * build the hashtable.
4816  */
4817  foreach(lc, hashclauses)
4818  {
4819  OpExpr *hclause = lfirst_node(OpExpr, lc);
4820 
4821  hashoperators = lappend_oid(hashoperators, hclause->opno);
4822  hashcollations = lappend_oid(hashcollations, hclause->inputcollid);
4823  outer_hashkeys = lappend(outer_hashkeys, linitial(hclause->args));
4824  inner_hashkeys = lappend(inner_hashkeys, lsecond(hclause->args));
4825  }
4826 
4827  /*
4828  * Build the hash node and hash join node.
4829  */
4830  hash_plan = make_hash(inner_plan,
4831  inner_hashkeys,
4832  skewTable,
4833  skewColumn,
4834  skewInherit);
4835 
4836  /*
4837  * Set Hash node's startup & total costs equal to total cost of input
4838  * plan; this only affects EXPLAIN display not decisions.
4839  */
4840  copy_plan_costsize(&hash_plan->plan, inner_plan);
4841  hash_plan->plan.startup_cost = hash_plan->plan.total_cost;
4842 
4843  /*
4844  * If parallel-aware, the executor will also need an estimate of the total
4845  * number of rows expected from all participants so that it can size the
4846  * shared hash table.
4847  */
4848  if (best_path->jpath.path.parallel_aware)
4849  {
4850  hash_plan->plan.parallel_aware = true;
4851  hash_plan->rows_total = best_path->inner_rows_total;
4852  }
4853 
4854  join_plan = make_hashjoin(tlist,
4855  joinclauses,
4856  otherclauses,
4857  hashclauses,
4858  hashoperators,
4859  hashcollations,
4860  outer_hashkeys,
4861  outer_plan,
4862  (Plan *) hash_plan,
4863  best_path->jpath.jointype,
4864  best_path->jpath.inner_unique);
4865 
4866  copy_generic_path_info(&join_plan->join.plan, &best_path->jpath.path);
4867 
4868  return join_plan;
4869 }
4870 
4871 
4872 /*****************************************************************************
4873  *
4874  * SUPPORTING ROUTINES
4875  *
4876  *****************************************************************************/
4877 
4878 /*
4879  * replace_nestloop_params
4880  * Replace outer-relation Vars and PlaceHolderVars in the given expression
4881  * with nestloop Params
4882  *
4883  * All Vars and PlaceHolderVars belonging to the relation(s) identified by
4884  * root->curOuterRels are replaced by Params, and entries are added to
4885  * root->curOuterParams if not already present.
4886  */
4887 static Node *
4888 replace_nestloop_params(PlannerInfo *root, Node *expr)
4889 {
4890  /* No setup needed for tree walk, so away we go */
4891  return replace_nestloop_params_mutator(expr, root);
4892 }
4893 
4894 static Node *
4895 replace_nestloop_params_mutator(Node *node, PlannerInfo *root)
4896 {
4897  if (node == NULL)
4898  return NULL;
4899  if (IsA(node, Var))
4900  {
4901  Var *var = (Var *) node;
4902 
4903  /* Upper-level Vars should be long gone at this point */
4904  Assert(var->varlevelsup == 0);
4905  /* If not to be replaced, we can just return the Var unmodified */
4906  if (IS_SPECIAL_VARNO(var->varno) ||
4907  !bms_is_member(var->varno, root->curOuterRels))
4908  return node;
4909  /* Replace the Var with a nestloop Param */
4910  return (Node *) replace_nestloop_param_var(root, var);
4911  }
4912  if (IsA(node, PlaceHolderVar))
4913  {
4914  PlaceHolderVar *phv = (PlaceHolderVar *) node;
4915 
4916  /* Upper-level PlaceHolderVars should be long gone at this point */
4917  Assert(phv->phlevelsup == 0);
4918 
4919  /*
4920  * Check whether we need to replace the PHV. We use bms_overlap as a
4921  * cheap/quick test to see if the PHV might be evaluated in the outer
4922  * rels, and then grab its PlaceHolderInfo to tell for sure.
4923  */
4924  if (!bms_overlap(phv->phrels, root->curOuterRels) ||
4925  !bms_is_subset(find_placeholder_info(root, phv, false)->ph_eval_at,
4926  root->curOuterRels))
4927  {
4928  /*
4929  * We can't replace the whole PHV, but we might still need to
4930  * replace Vars or PHVs within its expression, in case it ends up
4931  * actually getting evaluated here. (It might get evaluated in
4932  * this plan node, or some child node; in the latter case we don't
4933  * really need to process the expression here, but we haven't got
4934  * enough info to tell if that's the case.) Flat-copy the PHV
4935  * node and then recurse on its expression.
4936  *
4937  * Note that after doing this, we might have different
4938  * representations of the contents of the same PHV in different
4939  * parts of the plan tree. This is OK because equal() will just
4940  * match on phid/phlevelsup, so setrefs.c will still recognize an
4941  * upper-level reference to a lower-level copy of the same PHV.
4942  */
4943  PlaceHolderVar *newphv = makeNode(PlaceHolderVar);
4944 
4945  memcpy(newphv, phv, sizeof(PlaceHolderVar));
4946  newphv->phexpr = (Expr *)
4947  replace_nestloop_params_mutator((Node *) phv->phexpr,
4948  root);
4949  return (Node *) newphv;
4950  }
4951  /* Replace the PlaceHolderVar with a nestloop Param */
4952  return (Node *) replace_nestloop_param_placeholdervar(root, phv);
4953  }
4954  return expression_tree_mutator(node,
4955  replace_nestloop_params_mutator,
4956  (void *) root);
4957 }
4958 
4959 /*
4960  * fix_indexqual_references
4961  * Adjust indexqual clauses to the form the executor's indexqual
4962  * machinery needs.
4963  *
4964  * We have three tasks here:
4965  * * Select the actual qual clauses out of the input IndexClause list,
4966  * and remove RestrictInfo nodes from the qual clauses.
4967  * * Replace any outer-relation Var or PHV nodes with nestloop Params.
4968  * (XXX eventually, that responsibility should go elsewhere?)
4969  * * Index keys must be represented by Var nodes with varattno set to the
4970  * index's attribute number, not the attribute number in the original rel.
4971  *
4972  * *stripped_indexquals_p receives a list of the actual qual clauses.
4973  *
4974  * *fixed_indexquals_p receives a list of the adjusted quals. This is a copy
4975  * that shares no substructure with the original; this is needed in case there
4976  * are subplans in it (we need two separate copies of the subplan tree, or
4977  * things will go awry).
4978  */
4979 static void
4980 fix_indexqual_references(PlannerInfo *root, IndexPath *index_path,
4981  List **stripped_indexquals_p, List **fixed_indexquals_p)
4982 {
4983  IndexOptInfo *index = index_path->indexinfo;
4984  List *stripped_indexquals;
4985  List *fixed_indexquals;
4986  ListCell *lc;
4987 
4988  stripped_indexquals = fixed_indexquals = NIL;
4989 
4990  foreach(lc, index_path->indexclauses)
4991  {
4992  IndexClause *iclause = lfirst_node(IndexClause, lc);
4993  int indexcol = iclause->indexcol;
4994  ListCell *lc2;
4995 
4996  foreach(lc2, iclause->indexquals)
4997  {
4998  RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc2);
4999  Node *clause = (Node *) rinfo->clause;
5000 
5001  stripped_indexquals = lappend(stripped_indexquals, clause);
5002  clause = fix_indexqual_clause(root, index, indexcol,
5003  clause, iclause->indexcols);
5004  fixed_indexquals = lappend(fixed_indexquals, clause);
5005  }
5006  }
5007 
5008  *stripped_indexquals_p = stripped_indexquals;
5009  *fixed_indexquals_p = fixed_indexquals;
5010 }
5011 
5012 /*
5013  * fix_indexorderby_references
5014  * Adjust indexorderby clauses to the form the executor's index
5015  * machinery needs.
5016  *
5017  * This is a simplified version of fix_indexqual_references. The input is
5018  * bare clauses and a separate indexcol list, instead of IndexClauses.
5019  */
5020 static List *
5021 fix_indexorderby_references(PlannerInfo *root, IndexPath *index_path)
5022 {
5023  IndexOptInfo *index = index_path->indexinfo;
5024  List *fixed_indexorderbys;
5025  ListCell *lcc,
5026  *lci;
5027 
5028  fixed_indexorderbys = NIL;
5029 
5030  forboth(lcc, index_path->indexorderbys, lci, index_path->indexorderbycols)
5031  {
5032  Node *clause = (Node *) lfirst(lcc);
5033  int indexcol = lfirst_int(lci);
5034 
5035  clause = fix_indexqual_clause(root, index, indexcol, clause, NIL);
5036  fixed_indexorderbys = lappend(fixed_indexorderbys, clause);
5037  }
5038 
5039  return fixed_indexorderbys;
5040 }
5041 
5042 /*
5043  * fix_indexqual_clause
5044  * Convert a single indexqual clause to the form needed by the executor.
5045  *
5046  * We replace nestloop params here, and replace the index key variables
5047  * or expressions by index Var nodes.
5048  */
5049 static Node *
5050 fix_indexqual_clause(PlannerInfo *root, IndexOptInfo *index, int indexcol,
5051  Node *clause, List *indexcolnos)
5052 {
5053  /*
5054  * Replace any outer-relation variables with nestloop params.
5055  *
5056  * This also makes a copy of the clause, so it's safe to modify it
5057  * in-place below.
5058  */
5059  clause = replace_nestloop_params(root, clause);
5060 
5061  if (IsA(clause, OpExpr))
5062  {
5063  OpExpr *op = (OpExpr *) clause;
5064 
5065  /* Replace the indexkey expression with an index Var. */
5066  linitial(op->args) = fix_indexqual_operand(linitial(op->args),
5067  index,
5068  indexcol);
5069  }
5070  else if (IsA(clause, RowCompareExpr))
5071  {
5072  RowCompareExpr *rc = (RowCompareExpr *) clause;
5073  ListCell *lca,
5074  *lcai;
5075 
5076  /* Replace the indexkey expressions with index Vars. */
5077  Assert(list_length(rc->largs) == list_length(indexcolnos));
5078  forboth(lca, rc->largs, lcai, indexcolnos)
5079  {
5080  lfirst(lca) = fix_indexqual_operand(lfirst(lca),
5081  index,
5082  lfirst_int(lcai));
5083  }
5084  }
5085  else if (IsA(clause, ScalarArrayOpExpr))
5086  {
5087  ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
5088 
5089  /* Replace the indexkey expression with an index Var. */
5090  linitial(saop->args) = fix_indexqual_operand(linitial(saop->args),
5091  index,
5092  indexcol);
5093  }
5094  else if (IsA(clause, NullTest))
5095  {
5096  NullTest *nt = (NullTest *) clause;
5097 
5098  /* Replace the indexkey expression with an index Var. */
5099  nt->arg = (Expr *) fix_indexqual_operand((Node *) nt->arg,
5100  index,
5101  indexcol);
5102  }
5103  else
5104  elog(ERROR, "unsupported indexqual type: %d",
5105  (int) nodeTag(clause));
5106 
5107  return clause;
5108 }
5109 
5110 /*
5111  * fix_indexqual_operand
5112  * Convert an indexqual expression to a Var referencing the index column.
5113  *
5114  * We represent index keys by Var nodes having varno == INDEX_VAR and varattno
5115  * equal to the index's attribute number (index column position).
5116  *
5117  * Most of the code here is just for sanity cross-checking that the given
5118  * expression actually matches the index column it's claimed to.
5119  */
5120 static Node *
5121 fix_indexqual_operand(Node *node, IndexOptInfo *index, int indexcol)
5122 {
5123  Var *result;
5124  int pos;
5125  ListCell *indexpr_item;
5126 
5127  /*
5128  * Remove any binary-compatible relabeling of the indexkey
5129  */
5130  if (IsA(node, RelabelType))
5131  node = (Node *) ((RelabelType *) node)->arg;
5132 
5133  Assert(indexcol >= 0 && indexcol < index->ncolumns);
5134 
5135  if (index->indexkeys[indexcol] != 0)
5136  {
5137  /* It's a simple index column */
5138  if (IsA(node, Var) &&
5139  ((Var *) node)->varno == index->rel->relid &&
5140  ((Var *) node)->varattno == index->indexkeys[indexcol])
5141  {
5142  result = (Var *) copyObject(node);
5143  result->varno = INDEX_VAR;
5144  result->varattno = indexcol + 1;
5145  return (Node *) result;
5146  }
5147  else
5148  elog(ERROR, "index key does not match expected index column");
5149  }
5150 
5151  /* It's an index expression, so find and cross-check the expression */
5152  indexpr_item = list_head(index->indexprs);
5153  for (pos = 0; pos < index->ncolumns; pos++)
5154  {
5155  if (index->indexkeys[pos] == 0)
5156  {
5157  if (indexpr_item == NULL)
5158  elog(ERROR, "too few entries in indexprs list");
5159  if (pos == indexcol)
5160  {
5161  Node *indexkey;
5162 
5163  indexkey = (Node *) lfirst(indexpr_item);
5164  if (indexkey && IsA(indexkey, RelabelType))
5165  indexkey = (Node *) ((RelabelType *) indexkey)->arg;
5166  if (equal(node, indexkey))
5167  {
5168  result = makeVar(INDEX_VAR, indexcol + 1,
5169  exprType(lfirst(indexpr_item)), -1,
5170  exprCollation(lfirst(indexpr_item)),
5171  0);
5172  return (Node *) result;
5173  }
5174  else
5175  elog(ERROR, "index key does not match expected index column");
5176  }
5177  indexpr_item = lnext(index->indexprs, indexpr_item);
5178  }
5179  }
5180 
5181  /* Oops... */
5182  elog(ERROR, "index key does not match expected index column");
5183  return NULL; /* keep compiler quiet */
5184 }
5185 
5186 /*
5187  * get_switched_clauses
5188  * Given a list of merge or hash joinclauses (as RestrictInfo nodes),
5189  * extract the bare clauses, and rearrange the elements within the
5190  * clauses, if needed, so the outer join variable is on the left and
5191  * the inner is on the right. The original clause data structure is not
5192  * touched; a modified list is returned. We do, however, set the transient
5193  * outer_is_left field in each RestrictInfo to show which side was which.
5194  */
5195 static List *
5196 get_switched_clauses(List *clauses, Relids outerrelids)
5197 {
5198  List *t_list = NIL;
5199  ListCell *l;
5200 
5201  foreach(l, clauses)
5202  {
5203  RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(l);
5204  OpExpr *clause = (OpExpr *) restrictinfo->clause;
5205 
5206  Assert(is_opclause(clause));
5207  if (bms_is_subset(restrictinfo->right_relids, outerrelids))
5208  {
5209  /*
5210  * Duplicate just enough of the structure to allow commuting the
5211  * clause without changing the original list. Could use
5212  * copyObject, but a complete deep copy is overkill.
5213  */
5214  OpExpr *temp = makeNode(OpExpr);
5215 
5216  temp->opno = clause->opno;
5217  temp->opfuncid = InvalidOid;
5218  temp->opresulttype = clause->opresulttype;
5219  temp->opretset = clause->opretset;
5220  temp->opcollid = clause->opcollid;
5221  temp->inputcollid = clause->inputcollid;
5222  temp->args = list_copy(clause->args);
5223  temp->location = clause->location;
5224  /* Commute it --- note this modifies the temp node in-place. */
5225  CommuteOpExpr(temp);
5226  t_list = lappend(t_list, temp);
5227  restrictinfo->outer_is_left = false;
5228  }
5229  else
5230  {
5231  Assert(bms_is_subset(restrictinfo->left_relids, outerrelids));
5232  t_list = lappend(t_list, clause);
5233  restrictinfo->outer_is_left = true;
5234  }
5235  }
5236  return t_list;
5237 }
5238 
5239 /*
5240  * order_qual_clauses
5241  * Given a list of qual clauses that will all be evaluated at the same
5242  * plan node, sort the list into the order we want to check the quals
5243  * in at runtime.
5244  *
5245  * When security barrier quals are used in the query, we may have quals with
5246  * different security levels in the list. Quals of lower security_level
5247  * must go before quals of higher security_level, except that we can grant
5248  * exceptions to move up quals that are leakproof. When security level
5249  * doesn't force the decision, we prefer to order clauses by estimated
5250  * execution cost, cheapest first.
5251  *
5252  * Ideally the order should be driven by a combination of execution cost and
5253  * selectivity, but it's not immediately clear how to account for both,
5254  * and given the uncertainty of the estimates the reliability of the decisions
5255  * would be doubtful anyway. So we just order by security level then
5256  * estimated per-tuple cost, being careful not to change the order when
5257  * (as is often the case) the estimates are identical.
5258  *
5259  * Although this will work on either bare clauses or RestrictInfos, it's
5260  * much faster to apply it to RestrictInfos, since it can re-use cost
5261  * information that is cached in RestrictInfos. XXX in the bare-clause
5262  * case, we are also not able to apply security considerations. That is
5263  * all right for the moment, because the bare-clause case doesn't occur
5264  * anywhere that barrier quals could be present, but it would be better to
5265  * get rid of it.
5266  *
5267  * Note: some callers pass lists that contain entries that will later be
5268  * removed; this is the easiest way to let this routine see RestrictInfos
5269  * instead of bare clauses. This is another reason why trying to consider
5270  * selectivity in the ordering would likely do the wrong thing.
5271  */
5272 static List *
5273 order_qual_clauses(PlannerInfo *root, List *clauses)
5274 {
5275  typedef struct
5276  {
5277  Node *clause;
5278  Cost cost;
5279  Index security_level;
5280  } QualItem;
5281  int nitems = list_length(clauses);
5282  QualItem *items;
5283  ListCell *lc;
5284  int i;
5285  List *result;
5286 
5287  /* No need to work hard for 0 or 1 clause */
5288  if (nitems <= 1)
5289  return clauses;
5290 
5291  /*
5292  * Collect the items and costs into an array. This is to avoid repeated
5293  * cost_qual_eval work if the inputs aren't RestrictInfos.
5294  */
5295  items = (QualItem *) palloc(nitems * sizeof(QualItem));
5296  i = 0;
5297  foreach(lc, clauses)
5298  {
5299  Node *clause = (Node *) lfirst(lc);
5300  QualCost qcost;
5301 
5302  cost_qual_eval_node(&qcost, clause, root);
5303  items[i].clause = clause;
5304  items[i].cost = qcost.per_tuple;
5305  if (IsA(clause, RestrictInfo))
5306  {
5307  RestrictInfo *rinfo = (RestrictInfo *) clause;
5308 
5309  /*
5310  * If a clause is leakproof, it doesn't have to be constrained by
5311  * its nominal security level. If it's also reasonably cheap
5312  * (here defined as 10X cpu_operator_cost), pretend it has
5313  * security_level 0, which will allow it to go in front of
5314  * more-expensive quals of lower security levels. Of course, that
5315  * will also force it to go in front of cheaper quals of its own
5316  * security level, which is not so great, but we can alleviate
5317  * that risk by applying the cost limit cutoff.
5318  */
5319  if (rinfo->leakproof && items[i].cost < 10 * cpu_operator_cost)
5320  items[i].security_level = 0;
5321  else
5322  items[i].security_level = rinfo->security_level;
5323  }
5324  else
5325  items[i].security_level = 0;
5326  i++;
5327  }
5328 
5329  /*
5330  * Sort. We don't use qsort() because it's not guaranteed stable for
5331  * equal keys. The expected number of entries is small enough that a
5332  * simple insertion sort should be good enough.
5333  */
5334  for (i = 1; i < nitems; i++)
5335  {
5336  QualItem newitem = items[i];
5337  int j;
5338 
5339  /* insert newitem into the already-sorted subarray */
5340  for (j = i; j > 0; j--)
5341  {
5342  QualItem *olditem = &items[j - 1];
5343 
5344  if (newitem.security_level > olditem->security_level ||
5345  (newitem.security_level == olditem->security_level &&
5346  newitem.cost >= olditem->cost))
5347  break;
5348  items[j] = *olditem;
5349  }
5350  items[j] = newitem;
5351  }
5352 
5353  /* Convert back to a list */
5354  result = NIL;
5355  for (i = 0; i < nitems; i++)
5356  result = lappend(result, items[i].clause);
5357 
5358  return result;
5359 }
5360 
5361 /*
5362  * Copy cost and size info from a Path node to the Plan node created from it.
5363  * The executor usually won't use this info, but it's needed by EXPLAIN.
5364  * Also copy the parallel-related flags, which the executor *will* use.
5365  */
5366 static void
5367 copy_generic_path_info(Plan *dest, Path *src)
5368 {
5369  dest->startup_cost = src->startup_cost;
5370  dest->total_cost = src->total_cost;
5371  dest->plan_rows = src->rows;
5372  dest->plan_width = src->pathtarget->width;
5373  dest->parallel_aware = src->parallel_aware;
5374  dest->parallel_safe = src->parallel_safe;
5375 }
5376 
5377 /*
5378  * Copy cost and size info from a lower plan node to an inserted node.
5379  * (Most callers alter the info after copying it.)
5380  */
5381 static void
5382 copy_plan_costsize(Plan *dest, Plan *src)
5383 {
5384  dest->startup_cost = src->startup_cost;
5385  dest->total_cost = src->total_cost;
5386  dest->plan_rows = src->plan_rows;
5387  dest->plan_width = src->plan_width;
5388  /* Assume the inserted node is not parallel-aware. */
5389  dest->parallel_aware = false;
5390  /* Assume the inserted node is parallel-safe, if child plan is. */
5391  dest->parallel_safe = src->parallel_safe;
5392 }
5393 
5394 /*
5395  * Some places in this file build Sort nodes that don't have a directly
5396  * corresponding Path node. The cost of the sort is, or should have been,
5397  * included in the cost of the Path node we're working from, but since it's
5398  * not split out, we have to re-figure it using cost_sort(). This is just
5399  * to label the Sort node nicely for EXPLAIN.
5400  *
5401  * limit_tuples is as for cost_sort (in particular, pass -1 if no limit)
5402  */
5403 static void
5404 label_sort_with_costsize(PlannerInfo *root, Sort *plan, double limit_tuples)
5405 {
5406  Plan *lefttree = plan->plan.lefttree;
5407  Path sort_path; /* dummy for result of cost_sort */
5408 
5409  /*
5410  * This function shouldn't have to deal with IncrementalSort plans because
5411  * they are only created from corresponding Path nodes.
5412  */
5413  Assert(IsA(plan, Sort));
5414 
5415  cost_sort(&sort_path, root, NIL,
5416  lefttree->total_cost,
5417  lefttree->plan_rows,
5418  lefttree->plan_width,
5419  0.0,
5420  work_mem,
5421  limit_tuples);
5422  plan->plan.startup_cost = sort_path.startup_cost;
5423  plan->plan.total_cost = sort_path.total_cost;
5424  plan->plan.plan_rows = lefttree->plan_rows;
5425  plan->plan.plan_width = lefttree->plan_width;
5426  plan->plan.parallel_aware = false;
5427  plan->plan.parallel_safe = lefttree->parallel_safe;
5428 }
5429 
5430 /*
5431  * bitmap_subplan_mark_shared
5432  * Set isshared flag in bitmap subplan so that it will be created in
5433  * shared memory.
5434  */
5435 static void
5436 bitmap_subplan_mark_shared(Plan *plan)
5437 {
5438  if (IsA(plan, BitmapAnd))
5439  bitmap_subplan_mark_shared(linitial(((BitmapAnd *) plan)->bitmapplans));
5440  else if (IsA(plan, BitmapOr))
5441  {
5442  ((BitmapOr *) plan)->isshared = true;
5443  bitmap_subplan_mark_shared(linitial(((BitmapOr *) plan)->bitmapplans));
5444  }
5445  else if (IsA(plan, BitmapIndexScan))
5446  ((BitmapIndexScan *) plan)->isshared = true;
5447  else
5448  elog(ERROR, "unrecognized node type: %d", nodeTag(plan));
5449 }
5450 
5451 /*****************************************************************************
5452  *
5453  * PLAN NODE BUILDING ROUTINES
5454  *
5455  * In general, these functions are not passed the original Path and therefore
5456  * leave it to the caller to fill in the cost/width fields from the Path,
5457  * typically by calling copy_generic_path_info(). This convention is
5458  * somewhat historical, but it does support a few places above where we build
5459  * a plan node without having an exactly corresponding Path node. Under no
5460  * circumstances should one of these functions do its own cost calculations,
5461  * as that would be redundant with calculations done while building Paths.
5462  *
5463  *****************************************************************************/
5464 
5465 static SeqScan *
5466 make_seqscan(List *qptlist,
5467  List *qpqual,
5468  Index scanrelid)
5469 {
5470  SeqScan *node = makeNode(SeqScan);
5471  Plan *plan = &node->scan.plan;
5472 
5473  plan->targetlist = qptlist;
5474  plan->qual = qpqual;
5475  plan->lefttree = NULL;
5476  plan->righttree = NULL;
5477  node->scan.scanrelid = scanrelid;
5478 
5479  return node;
5480 }
5481 
5482 static SampleScan *
5483 make_samplescan(List *qptlist,
5484  List *qpqual,
5485  Index scanrelid,
5486  TableSampleClause *tsc)
5487 {
5488  SampleScan *node = makeNode(SampleScan);
5489  Plan *plan = &node->scan.plan;
5490 
5491  plan->targetlist = qptlist;
5492  plan->qual = qpqual;
5493  plan->lefttree = NULL;
5494  plan->righttree = NULL;
5495  node->scan.scanrelid = scanrelid;
5496  node->tablesample = tsc;
5497 
5498  return node;
5499 }
5500 
5501 static IndexScan *
5502 make_indexscan(List *qptlist,
5503  List *qpqual,
5504  Index scanrelid,
5505  Oid indexid,
5506  List *indexqual,
5507  List *indexqualorig,
5508  List *indexorderby,
5509  List *indexorderbyorig,
5510  List *indexorderbyops,
5511  ScanDirection indexscandir)
5512 {
5513  IndexScan *node = makeNode(IndexScan);
5514  Plan *plan = &node->scan.plan;
5515 
5516  plan->targetlist = qptlist;
5517  plan->qual = qpqual;
5518  plan->lefttree = NULL;
5519  plan->righttree = NULL;
5520  node->scan.scanrelid = scanrelid;
5521  node->indexid = indexid;
5522  node->indexqual = indexqual;
5523  node->indexqualorig = indexqualorig;
5524  node->indexorderby = indexorderby;
5525  node->indexorderbyorig = indexorderbyorig;
5526  node->indexorderbyops = indexorderbyops;
5527  node->indexorderdir = indexscandir;
5528 
5529  return node;
5530 }
5531 
5532 static IndexOnlyScan *
5533 make_indexonlyscan(List *qptlist,
5534  List *qpqual,
5535  Index scanrelid,
5536  Oid indexid,
5537  List *indexqual,
5538  List *recheckqual,
5539  List *indexorderby,
5540  List *indextlist,
5541  ScanDirection indexscandir)
5542 {
5543  IndexOnlyScan *node = makeNode(IndexOnlyScan);
5544  Plan *plan = &node->scan.plan;
5545 
5546  plan->targetlist = qptlist;
5547  plan->qual = qpqual;
5548  plan->lefttree = NULL;
5549  plan->righttree = NULL;
5550  node->scan.scanrelid =